Zn metal anodes are usually subject to grave dendrite growth during platting/stripping, which dramatically curtails the lifespan of aqueous Zn-ion batteries and capacitors. To address above problems, in our work, a novel phosphorus-functionalized multichannel carbon interlayer was designed and covered on Zn anodes. The results demonstrated that the multichannel structure combined with the three-dimensional meshy skeleton can provide more sufficient space for Zn deposition, thereby effectively inhibiting the growth of zinc dendrites. Meanwhile, theoretical calculations also confirmed that the P–C and P=O functional groups from phosphorus-functionalized multichannel carbon interlayer have the decisive influence in reducing the zinc nucleation potential and depositing uniformly zinc. Concretely, the symmetrical battery assembled with phosphorus-functionalized multichannel carbon interlayer-covered Zn anodes possessed a long lifetime of 3300 h at 2 mA cm^-2 with 1 mAh cm^-2. Furthermore, the full cell with activated carbon cathodes exhibited a high specific capacity of 80.5 mAh g^-1 and outstanding cycling stability without capacity decay after 15 000 cycles at a high current density of 5 A g^-1. The superior electrochemical performance exceeded that of most reported papers. Consequently, our synthesized zincophilic interlayer with the unique structure has superior prospects for application in stabilizing zinc anodes and prolonging the lifespan of batteries.

Calcium-ion batteries have been considered attractive candidates for large-scale energy storage applications due to their natural abundance and low redox potential of Ca²⁺/Ca. However, current calcium ion technology is still hampered by the lack of high-capacity and long-life electrode materials to accommodate the large Ca²⁺ (1.00 Å). Herein, an amorphous vanadium structure induced by Mo doping and in-situ electrochemical activation is reported as a high-rate anode material for calcium ion batteries. The doping of Mo could destroy the lattice stability of VS₄ material, enhancing the flexibility of the structure. The following electrochemical activation further converted the material into sulfide and oxides co-dominated composite (defined as MoVSO), which serves as an active material for the storage of Ca²⁺ during cycling. Consequently, this amorphous vanadium structure exhibits excellent rate capability, achieving discharge capacities of 306.7 and 149.2 mAh g^-1 at 5 and 50 A g^-1 and an ultra-long cycle life of 2000 cycles with 91.2% capacity retention. These values represent the highest level to date reported for calcium ion batteries. The mechanism studies show that the material undergoes a partial phase transition process to derive MoVSO. This work unveiled the calcium storage mechanism of vanadium sulfide in aqueous electrolytes and accelerated the development of high-performance aqueous calcium ion batteries.

Since 2019, research into MXene derivatives has seen a dramatic rise; further progress requires a rational design for specific functionality. Herein, through a molecular design by selecting suitable functional groups in the MXene coating, we have implemented the dual N doping of the derivatives, nitrogen-doped TiO₂@nitrogen-doped carbon nanosheets (N-TiO₂@NC), to strike a balance between the active anatase TiO₂ at low temperatures, and carbon activation at high temperatures. The NH₃ reduction environment generated at 400 °C as evidenced by the in situ pyrolysis SVUV-PIMS process is crucial for concurrent phase engineering. With both electrical conductivity and surface Na⁺ availability, the N-TiO₂@NC achieves higher interface capacitive-like sodium storage with long-term stability. More than 100 mAh g^-1 is achieved at 2 A g^-1 after 5000 cycles. The proposed design may be extended to other MXenes and solidify the growing family of MXene derivatives for energy storage.

Understanding the correlation between the fundamental descriptors and catalytic performance is meaningful to guide the design of high-performance electrochemical catalysts. However, exploring key factors that affect catalytic performance in the vast catalyst space remains challenging for people. Herein, to accurately identify the factors that affect the performance of N₂ reduction, we apply interpretable machine learning (ML) to analyze high-throughput screening results, which is also suited to other surface reactions in catalysis. To expound on the paradigm, 33 promising catalysts are screened from 168 carbon-supported candidates, specifically single-atom catalysts (SACs) supported by a BC₃ monolayer (TM@V_B/C-N_{n = 0–3}-BC₃) via high-throughput screening. Subsequently, the hybrid sampling method and XGBoost model are selected to classify eligible and non-eligible catalysts. Through feature interpretation using Shapley Additive Explanations (SHAP) analysis, two crucial features, that is, the number of valence electrons (N_v) and nitrogen substitution (N_n), are screened out. Combining SHAP analysis and electronic structure calculations, the synergistic effect between an active center with low valence electron numbers and reasonable C-N coordination (a medium fraction of nitrogen substitution) can exhibit high catalytic performance. Finally, six superior catalysts with a limiting potential lower than -0.4 V are predicted. Our workflow offers a rational approach to obtaining key information on catalytic performance from high-throughput screening results to design efficient catalysts that can be applied to other materials and reactions.

Most organic electrode materials (OEMs) for rechargeable batteries employ n-type redox centers, whose redox potentials are intrinsically limited <3.0 V versus Li⁺/Li. However, p-type materials possessing high redox potentials experience low specific capacities because they are capable of only a single redox reaction within the stable electrochemical window of typical electrolytes. Herein, we report 5,11-diethyl-5,11-dihydroindolo[3,2-b]carbazole (DEICZ) as a novel p-type OEM, exhibiting stable plateaus at high discharge potentials of 3.44 and 4.09 V versus Li⁺/Li. Notably, the second redox potential of DEICZ is within the stable electrochemical window. The mechanism of the double redox reaction is investigated using both theoretical calculations and experimental measurements, including density functional theory calculations, ex situ electron spin resonance, and X-ray photoelectron spectroscopy. Finally, hybridization with single-walled carbon nanotubes (SWCNT) improves the cycle stability and rate performance of DEICZ owing to the π–π interactions between the SWCNT and co-planar molecular structure of DEICZ, preventing the dissolution of active materials into the electrolyte. The DEICZ/SWCNT composite electrode maintains 70.4% of its initial specific capacity at 1-C rate and also exhibits high-rate capability, even performing well at 100-C rate. Furthermore, we demonstrate its potential for flexible batteries after applying 1000 bending stresses to the composite electrode.

In engineering practice, the output performance of contact separation TENGs (CS-TENGs) increases with the increase of tribo-pair area, which includes increasing the size of single layer CS-TENGs (SCS-TENGs) or the number of units (zigzag TENGs). However, such two strategies show significant differences in output power and power density. In this study, to seek a universal CS-TENG design solution, the output performance of a SCS-TENG and a zigzag TENG (Z-TENG) is systematically compared, including voltage, current, transferred charge, instantaneous power density, and charging power density. The relationship between contact area and output voltages is explored, and the output voltage equation is fitted. The experimental results reveal that SCS-TENGs yield better performance than Z-TENGs in terms of voltage, power, and power density under the same total contact area. Z-TENGs show energy loss during the transfer of mechanical energy, and such loss is aggravated by the increasing number of units. The instantaneous peak power of the SCS-TENG is up to 22 times that of the Z-TENG (45 cm²). Furthermore, the power density of capacitor charging of SCS-TENGs is 131% of that of Z-TENGs, which are relatively close. Z-TENG is a feasible alternative when the working space is limited.

Wearable triboelectric nanogenerators (TENGs) have attracted attention owing to their ability to harvest energy from the surrounding environment without maintenance. Herein, polyetherimide–Al₂O₃ (PAl) and polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP, PH) nanofiber membranes were used as tribo-positive and tribo-negative materials, respectively. Phytic acid-doped polyaniline (PANI)/cotton fabric (PPCF) and ethylenediamine (EDA)-crosslinked PAl (EPAl) nanofiber membranes were used as triboelectrode and triboencapsulation materials, respectively. The result showed that when the PAl–PH-based TENG was shaped as a circle with a radius of 1 cm, under the pressure of 50 N, and the frequency of 0.5 Hz, the open-circuit voltage (V_oc) and short-circuit current (I_sc) reached the highest value of 66.6 V and -93.4 to 110.1 nA, respectively. Moreover, the PH-based TENG could be used as a fabric sensor to detect fabric composition and as a sensor-inductive switch for light bulbs or beeping warning devices. When the PAl–PH-based TENG was shaped as a 5 × 5 cm² rectangle, a 33 µF capacitor could be charged to 15 V in 28 s. Interestingly, compared to PAl nanofiber membranes, EPAl nanofiber membranes exhibited good dyeing properties and excellent solvent resistance. The PPCF exhibited <5% resistance change after washing, bending, and stretching.

Heterogeneous catalysts promoting efficient production of reactive species and dynamically stabilized electron transfer mechanisms for peroxomonosulfates (PMS) still lack systematic investigation. Herein, a more stable magnetic layered double oxides (CFLDO/N-C), was designed using self-polymerization and high temperature carbonization of dopamine. The CFLDO/N-C/PMS system effectively activated PMS to remove 99% (k = 0.737 min^-1) of tetracycline (TC) within 10 min. The CFLDO/N-C/PMS system exhibited favorable resistance to inorganic anions and natural organics, as well as satisfactory suitability for multiple pollutants. The magnetic properties of the catalyst facilitated the separation of catalysts from the liquid phase, resulting in excellent reproducibility and effectively reducing the leaching of metal ions. An electronic bridge was constructed between cobalt (the active platform of the catalyst) and PMS, inducing PMS to break the O–O bond to generate the active species. The combination of static analysis and dynamic evolution confirmed the effective adsorption of PMS on the catalyst surface as well as the strong radical-assisted electron transfer process. Eventually, we further identified the sites where the reactive species attacked the TC and evaluated the toxicity of the intermediates. These findings offer innovative insights into the rapid degradation of pollutants achieved by transition metals in SR-AOPs and its mechanistic elaboration.

The development of active water oxidation catalysts for water splitting has stimulated considerable interest. Herein, the design and building of single atom Co sites using a supramolecular tailoring strategy are reported, that is, the introduction of pillar[4]arene[1]quinone (P4A1Q) permits mononuclear Co species stereoelectronically assembled on MoS₂ matrix to construct an atomically dispersed MoS₂@Co catalyst with modulated local electronic structure, definite chemical environment and enhanced oxygen evolution reaction performance. Theoretical calculations indicate that immsobilized single-Co sites exhibit an optimized adsorption capability of oxygen-containing intermediates, endowing the catalyst an excellent electrocatalytic oxygen evolution reaction activity, with a low overpotential of 370 mV at 10 mA cm^-2 and a small Tafel slope of 90 mV dec^-1. The extendable potential of this strategy to other electrocatalysts such as MoS₂@Ni and MoS₂@Zn, and other applications such as the hydrogen evolution reaction was also demonstrated. This study affords new insights into the rational design of single metal atom systems with enhanced electrocatalytic performance.

Piezo-photocatalysis could coalesce the advantages of mechanical vibration and solar energy perfectly to achieve high-efficiency catalytic activity. Herein, the quintessential piezoelectric material CdS nanowires with different aspect ratios are precisely constructed and applied for piezo-photocatalytic reduction of U(VI) for the first time. The ultrasonic (60 kHz, 100 W) induces piezoelectric potential to generate a 0.57 eV A^-1 electric field, which is added to the direction of CdS (010) as a driving force to efficiently separate photogenerated charges. The alliance between piezoelectric effect and photocatalytic activity endows CdS NW-3 with the fastest piezo-photocatalytic rate under ultrasonic vibration and 5 W LED irradiation, and the relevant rate constant (0.042 min^-1) is about 12 and 53.8 times than that of LED and ultrasonication. More importantly, 93.74% of U(VI) could be removed from natural uranium mine wastewater. Therefore, this piezo-photocatalysis system that reduces U(VI) to easily separable (UO₂)O₂·2H₂O(s) provides valuable input for disposal applications of radioactive wastewater and broadens the horizons of nuclear energy utilization toward the advancement of carbon neutrality.

The rapid development of stretchable electronics made by circuits, microchips, and encapsulation elastomers has caused the production of a large amount of electronic waste (e-waste). The degradation of elastomers can highly minimize the negative effects of e-wastes. However, chemicals that included acid, alkali, and organics were repeatedly used during the recycling process, which were environmentally unfriendly. Here, a water-modulation-degradation-reconstruction (WDR) polyvinylpyrrolidone (PVP)-honey composite (PHC) polymer-gel was developed and could be regarded as encapsulation elastomers to realize a fully recyclable water-degradable stretchable (WS) electronics with multi-functions. The stretchability of the PHC polymer-gel could be modulated by the change of its water retention. The Chip-integrated liquid metal (LM) circuits encapsulated with the modulated PHC encapsulation elastomer could withstand a strain value of ∼3000%. Moreover, we developed a WS biomedical sensor composed of PHC encapsulation elastomer, LM circuits, and microchips, which could be fully recycled by biodegrading it in water to reconstruct a new one. As before, the reconstructed WS biomedical sensor could still simultaneously realize the combination of ultra-stretchability, recycling, self-healing, self-adhesive, and self-conformal abilities. The results revealed that this study exercises a profound influence on the rational design of multi-functional WS electronics.

Aqueous zinc-ion batteries are regarded as the promising candidates for large-scale energy storage systems owing to low cost and high safety; however, their applications are restricted by their poor low-temperature performance. Herein, a low-temperature electrolyte for low-temperature aqueous zinc-ion batteries is designed by introducing low-polarity diglyme into an aqueous solution of Zn(ClO₄)₂. The diglyme disrupts the hydrogen-bonding network of water and lowers the freezing point of the electrolyte to -105 °C. The designed electrolyte achieves ionic conductivity up to 16.18 mS cm^-1 at -45 °C. The diglyme and ClO₄^- reconfigure the solvated structure of Zn²⁺, which is more favorable for the desolvation of Zn²⁺ at low temperatures. In addition, the diglyme effectively suppresses the dendrites, hydrogen evolution reaction, and by-products of the zinc anode, improving the cycle stability of the battery. At -20 °C, a Zn‖Zn symmetrical cell is cycled for 5200 h at 1 mA cm^-2 and 1 mA h cm^-2, and a Zn‖polyaniline battery achieves an ultra-long cycle life of 10 000 times. This study sheds light on the future design of electrolytes with high ionic conductivity and easy desolvation at low temperatures for rechargeable batteries.

The accurate representation of lithium plating and aging phenomena has posed a persistent challenge within the battery research community. Empirical evidence underscores the pivotal role of cell structure in influencing aging behaviors and lithium plating within lithium-ion batteries (LIBs). Available lithium-ion plating models often falter in detailed description when integrating the structural intricacies. To address this challenge, this study proposes an innovative hierarchical model that intricately incorporates the layered rolling structure in cells. Notably, our model demonstrates a remarkable capacity to predict the non-uniform distribution of current density and overpotential along the rolling direction of LIBs. Subsequently, we delve into an insightful exploration of the structural factors that influence lithium plating behavior, leveraging the foundation laid by our established model. Furthermore, we easily update the hierarchical model by considering aging factors. This aging model effectively anticipates capacity fatigue and lithium plating tendencies across individual layers of LIBs, all while maintaining computational efficiency. In light of our findings, this model yields novel perspectives on capacity fatigue dynamics and local lithium plating behaviors, offering a substantial advancement compared to existing models. This research paves the way for more efficient and tailored LIB design and operation, with broad implications for energy storage technologies.

The development of high-performance organic solar cells (OSCs) with high operational stability is essential to accelerate their commercialization. Unfortunately, our understanding of the origin of instabilities in state-of-the-art OSCs based on bulk heterojunction (BHJ) featuring non-fullerene acceptors (NFAs) remains limited. Herein, we developed NFA-based OSCs using different charge extraction interlayer materials and studied their storage, thermal, and operational stabilities. Despite the high power conversion efficiency (PCE) of the OSCs (17.54%), we found that cells featuring self-assembled monolayers (SAMs) as hole-extraction interlayers exhibited poor stability. The time required for these OSCs to reach 80% of their initial performance (T₈₀) was only 6 h under continuous thermal stress at 85 °C in a nitrogen atmosphere and 1 h under maximum power point tracking (MPPT) in a vacuum. Inserting MoO_x between ITO and SAM enhanced the T₈₀ to 50 and ∼15 h after the thermal and operational stability tests, respectively, while maintaining a PCE of 16.9%. Replacing the organic PDINN electron transport layer with ZnO NPs further enhances the cells’ thermal and operational stability, boosting the T₈₀ to 1000 and 170 h, respectively. Our work reveals the synergistic roles of charge-selective interlayers and device architecture in developing efficient and stable OSCs.

Organic perovskites are promising semiconductor materials for advanced photoelectric applications. Their fluorescence typically shows a negative temperature coefficient due to bandgap change and structural instability. In this study, a novel perovskite-based composite with positive sensitivity to temperature was designed and obtained based on its inverse temperature crystallization, demonstrating good flexibility and solution processability. The supercritical drying method was used to address the limitations of annealing drying in preparing high-performance perovskite. Optimizing the precursor composition proved to be an effective approach for achieving high fluorescence and structural integrity in the perovskite material. This perovskite-based composite exhibited a positive temperature sensitivity of 28.563% °C^-1 for intensity change and excellent temperature cycling reversibility in the range of 25–40 °C in an ambient environment. This made it suitable for use as a smart window with rapid response. Furthermore, the perovskite composite was found to offer temperature-sensing photoluminescence and flexible processability due to its components of perovskite-based compounds and polyethylene oxide. The organic precursor solvent could be a promising candidate for use as ink to print or write on various substrates for optoelectronic devices responding to temperature.

In this work, we reported a series of monolithic 3D-printed Ni–Mo alloy electrodes for highly efficient water splitting at high current density (1500 mA cm^-2) with excellent stability, which provides a solution to scale up Ni–Mo catalysts for HER to industry use. All possible Ni–Mo metal/alloy phases were achieved by tuning the atomic composition and heat treatment procedure, and they were investigated through both experiment and simulation, and the optimal NiMo phase shows the best performance. Density functional theory (DFT) calculations elucidate that the NiMo phase has the lowest H₂O dissociation energy, which further explains the exceptional performance of NiMo. In addition, the microporosity was modulated via controlled thermal treatment, indicating that the 1100 °C sintered sample has the best catalytic performance, which is attributed to the high electrochemically active surface area (ECSA). Finally, the four different macrostructures were achieved by 3D printing, and they further improved the catalytic performance. The gyroid structure exhibits the best catalytic performance of driving 500 mA cm^-2 at a low overpotential of 228 mV and 1500 mA cm^-2 at 325 mV, as it maximizes the efficient bubble removal from the electrode surface, which offers the great potential for high current density water splitting.

High-temperature CO₂ electrolysis via solid oxide electrolysis cells (CO₂–SOECs) has drawn special attention due to the high energy convention efficiency, fast electrode kinetics, and great potential in carbon cycling. However, the development of cathode materials with high catalytic activity and chemical stability for pure CO₂ electrolysis is still a great challenge. In this work, A-site cation deficient dual-phase material, namely (Pr_0.4Ca_0.6)_xFe_0.8Ni_0.2O_3–δ (PCFN, x = 1, 0.95, and 0.9), has been designed as the fuel electrode for a pure CO₂–SOEC, which presents superior electrochemical performance. Among all these compositions, (Pr_0.4Ca_0.6)_0.95Fe_0.8Ni_0.2O_3–δ (PCFN95) exhibited the lowest polarization resistance of 0.458 Ω cm² at open-circuit voltage and 800 °C. The application of PCFN95 as the cathode in a single cell yields an impressive electrolysis current density of 1.76 A cm^-2 at 1.5 V and 800 °C, which is 76% higher than that of single cells with stoichiometric Pr_0.4Ca_0.6Fe_0.8Ni_0.2O_3–δ (PCFN100) cathode. The effects of A-site deficiency on materials’ phase structure and physicochemical properties are also systematically investigated. Such an enhancement in electrochemical performance is attributed to the promotion of effective CO₂ adsorption, as well as the improved electrode kinetics resulting from the A-site deficiency.

Anion exchange membrane fuel cell (AEMFC) technology is attracting intensive attention, due to its great potential by using non-precious-metal catalysts (NPMCs) in the cathode and cheap bipolar plate materials in alkaline media. However, in such case, the kinetics of hydrogen oxidation reaction (HOR) in the anode is two orders of magnitude sluggish than that of acidic electrolytes, which is recognized as the grand challenge in this field. Herein, we report the rationally designed Ni nanoparticles encapsulated by N-doped graphene layers (Ni@NG) using a facile pyrolysis strategy. Based on the density functional theory calculations and electrochemical performance analysis, it is witnessed that the rich Pyridinic-N within the graphene shell optimizes the binding energy of the intermediates, thus enabling the fundamentally enhanced activity for HOR with robust stability. As a proof of concept, the resultant Ni@NG sample as the anode with a low loading (1.8 mg cm^-2) in AEMFCs delivers a high peak power density of 500 mW cm^-2, outperforming all of those of NPMC-based analogs ever reported.

Solid oxide electrolysis cells (SOECs), displaying high current density and energy efficiency, have been proven to be an effective technique to electrochemically reduce CO₂ into CO. However, the insufficiency of cathode activity and stability is a tricky problem to be addressed for SOECs. Hence, it is urgent to develop suitable cathode materials with excellent catalytic activity and stability for further practical application of SOECs. Herein, a reduced perovskite oxide, Pr_0.35Sr_0.6Fe_0.7Cu_0.2Mo_0.1O_3-δ (PSFCM0.35), is developed as SOECs cathode to electrolyze CO₂. After reduction in 10% H₂/Ar, Cu and Fe nanoparticles are exsolved from the PSFCM0.35 lattice, resulting in a phase transformation from cubic perovskite to Ruddlesden–Popper (RP) perovskite with more oxygen vacancies. The exsolved metal nanoparticles are tightly attached to the perovskite substrate and afford more active sites to accelerate CO₂ adsorption and dissociation on the cathode surface. The significantly strengthened CO₂ adsorption capacity obtained after reduction is demonstrated by in situ Fourier transform-infrared (FT-IR) spectra. Symmetric cells with the reduced PSFCM0.35 (R-PSFCM0.35) electrode exhibit a low polarization resistance of 0.43 Ω cm² at 850 °C. Single electrolysis cells with the R-PSFCM0.35 cathode display an outstanding current density of 2947 mA cm^-2 at 850 °C and 1.6 V. In addition, the catalytic stability of the R-PSFCM0.35 cathode is also proved by operating at 800 °C with an applied constant current density of 600 mA cm^-2 for 100 h.

Symmetrical solid oxide cells (SSOCs) are very useful for energy generation and conversion. To fabricate the electrode of SSOC, it is very time-consuming to use the conventional approach. In this work, we design and develop a novel method, extreme heat treatment (EHT), to rapidly fabricate electrodes for SSOC. We show that by using the EHT method, the electrode can be fabricated in seconds (the fastest method to date), benefiting from enhanced reaction kinetics. The EHT-fabricated electrode presents a porous structure and good adhesion with the electrolyte. In contrast, tens of hours are needed to prepare the electrode by the conventional approach, and the prepared electrode exhibits a dense structure with a larger particle size due to the lengthy treatment. The EHT-fabricated electrode shows desirable electrochemical performance. Moreover, we show that the electrocatalytic activity of the perovskite electrode can be tuned by the vigorous approach of fast exsolution, deriving from the increased active sites for enhancing the electrochemical reactions. At 900 °C, a promising peak power density of 966 mW cm^-2 is reached. Our work exploits a new territory to fabricate and develop advanced electrodes for SSOCs in a rapid and high-throughput manner.

FeS₂ cathode is promising for all-solid-state lithium batteries due to its ultra-high capacity, low cost, and environmental friendliness. However, the poor performances, induced by limited electrode-electrolyte interface, severe volume expansion, and polysulfide shuttle, hinder the application of FeS₂ in all-solid-state lithium batteries. Herein, an integrated 3D FeS₂ electrode with full infiltration of Li₆PS₅Cl sulfide electrolytes is designed to address these challenges. Such a 3D integrated design not only achieves intimate and maximized interfacial contact between electrode and sulfide electrolytes, but also effectively buffers the inner volume change of FeS₂ and completely eliminates the polysulfide shuttle through direct solid–solid conversion of Li₂S/S. Besides, the vertical 3D arrays guarantee direct electron transport channels and horizontally shortened ion diffusion paths, endowing the integrated electrode with a remarkably reduced interfacial impedance and enhanced reaction kinetics. Benefiting from these synergies, the integrated all-solid-state lithium battery exhibits the largest reversible capacity (667 mAh g^-1), best rate performance, and highest capacity retention of 82% over 500 cycles at 0.1 C compared to both a liquid battery and non-integrated all-solid-state lithium battery. The cycling performance is among the best reported for FeS₂-based all-solid-state lithium batteries. This work presents an innovative synergistic strategy for designing long-cycling high-energy all-solid-state lithium batteries, which can be readily applied to other battery systems, such as lithium-sulfur batteries.

The systematic advances in the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs) have been driven by the developments of perovskite materials, electron transport layer (ETL) materials, and interfacial passivation between the relevant layers. While zinc oxide (ZnO) is a promising ETL in thin film photovoltaics, it is still highly desirable to develop novel synthetic methods that allow both fine-tuning the versatility of ZnO nanomaterials and improving the ZnO/perovskite interface. Among various inorganic and organic additives, zwitterions have been effectively utilized to passivate the perovskite films. In this vein, we develop novel, well-characterized betaine-coated ZnO QDs and use them as an ETL in the planar n-i-p PSC architecture, combining the ZnO QDs-based ETL with the ZnO/perovskite interface passivation by a series of ammonium halides (NH₄X, where X = F, Cl, Br). The champion device with the NH₄F passivation achieves one of the highest performances reported for ZnO-based PSCs, exhibiting a maximum PCE of ∼22% with a high fill factor of 80.3% and competitive stability, retaining ∼78% of its initial PCE under 1 Sun illumination with maximum power tracking for 250 h.

KVPO₄F with excellent structural stability and high operating voltage has been identified as a promising cathode for potassium-ion batteries (PIBs), but limits in sluggish ion transport and severe volume change cause insufficient potassium storage capability. Here, a high-energy and low-strain KVPO₄F composite cathode assisted by multifunctional K₂C₄O₄ electrode stabilizer is exquisitely designed. Systematical electrochemical investigations demonstrate that this composite cathode can deliver a remarkable energy density up to 530 Wh kg^-1 with 142.7 mAh g^-1 of reversible capacity at 25 mA g^-1, outstanding rate capability of 70.6 mAh g^-1 at 1000 mA g^-1, and decent cycling stability. Furthermore, slight volume change (∼5%) and increased interfacial stability with thin and even cathode–electrolyte interphase can be observed through in situ and ex situ characterizations, which are attributed to the synergistic effect from in situ potassium compensation and carbon deposition through self-sacrificing K₂C₄O₄ additive. Moreover, potassium-ion full cells manifest significant improvement in energy density and cycling stability. This work demonstrates a positive impact of K₂C₄O₄ additive on the comprehensive electrochemical enhancement, especially the activation of high-voltage plateau capacity and provides an efficient strategy to enlighten the design of other high-voltage cathodes for advanced high-energy batteries.

The undesirable capacity loss after first cycle is universal among layered cathode materials, which results in the capacity and energy decay. The key to resolving this obstacle lies in understanding the effect and origin of specific active Li sites during discharge process. In this study, focusing on Ah-level pouch cells for reliability, an ultrahigh initial Coulombic efficiency (96.1%) is achieved in an archetypical Li-rich layered oxide material. Combining the structure and electrochemistry analysis, we demonstrate that the achievement of high-capacity reversibility is a kinetic effect, primarily related to the sluggish Li mobility during oxygen reduction. Activating oxygen reduction through small density would induce the oxygen framework contraction, which, according to Pauli repulsion, imposes a great repulsive force to hinder the transport of tetrahedral Li. The tetrahedral Li storage upon deep oxygen reduction is experimentally visualized and, more importantly, contributes to 6% Coulombic efficiency enhancement as well as 10% energy density improvement for pouch cells, which shows great potentials breaking through the capacity and energy limitation imposed by intercalation chemistry.

Single-atom catalysts (SACs) have received significant interest for optimizing metal atom utilization and superior catalytic performance in hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR). In this study, we investigate a range of single-transition metal (STM₁ = Sc₁, Ti₁, V₁, Cr₁, Mn₁, Fe₁, Co₁, Ni₁, Cu₁, Zr₁, Nb₁, Mo₁, Ru₁, Rh₁, Pd₁, Ag₁, W₁, Re₁, Os₁, Ir₁, Pt₁, and Au₁) atoms supported on graphyne (GY) surface for HER/OER and ORR using first-principle calculations. Ab initio molecular dynamics (AIMD) simulations and phonon dispersion spectra reveal the dynamic and thermal stabilities of the GY surface. The exceptional stability of all supported STM₁ atoms within the H1 cavity of the GY surface exists in an isolated form, facilitating the uniform distribution and proper arrangement of single atoms on GY. In particular, Sc₁, Co₁, Fe₁, and Au₁/GY demonstrate promising catalytic efficiency in the HER due to idealistic ΔG_H* values via the Volmer-Heyrovsky pathway. Notably, Sc₁ and Au₁/GY exhibit superior HER catalytic activity compared to other studied catalysts. Co₁/GY catalyst exhibits higher selectivity and activity for the OER, with an overpotential (0.46 V) comparable to MoC₂, IrO₂, and RuO₂. Also, Rh₁ and Co₁/GY SACs exhibited promising electrocatalysts for the ORR, with an overpotential of 0.36 and 0.46 V, respectively. Therefore, Co₁/GY is a versatile electrocatalyst for metal-air batteries and water-splitting. This study further incorporates computational analysis of the kinetic potential energy barriers of Co₁ and Rh₁ in the OER and ORR. A strong correlation is found between the estimated kinetic activation barriers for the thermodynamic outcomes and all proton-coupled electron transfer steps. We establish a relation for the Gibbs free energy of intermediates to understand the mechanism of SACs supported on STM₁/GY and introduce a key descriptor. This study highlights GY as a favorable single-atom support for designing highly active and cost-effective versatile electrocatalysts for practical applications.

Solar irradiation can efficiently promote the kinetics of the oxygen evolution reaction (OER) during water splitting, where heterojunction catalysts exhibit excellent photoresponsive properties. However, insights into the origins of photoassisted OER catalysis remain unclear, especially the interfaced promotion under convergent solar irradiation (CSI). Herein, novel allotropic Co_5.47N/CoN heterojunctions were synthesized, and corresponding OER mechanisms under CSI were comprehensively uncovered from physical and chemical aspects using the in situ Raman technique and electrochemical cyclic voltammetry method. Our results provide a unique mechanism where high-energy UV light promotes the Co^3+/4+ conversion process in addition to the ordinary photoelectric effect excitation of the Co²⁺ material. Importantly, visible light under CSI can produce a photothermal effect for Co²⁺ excitation and Co^3+/4+ conversion, which promotes the OER significantly more than the usual photoelectric effect. As a result, Co_5.47N/CoN (containing 28% CoN) obtained 317.9% OER enhancement, which provides a pathway for constructing excellent OER catalysts.

The electrochemical coupling of biomass oxidation and nitrogen conversion presents a potential strategy for high value-added chemicals and nitrogen cycling. Herein, in this work, CuO/Co₃O₄ with heterogeneous interface is successfully constructed as a bifunctional catalyst for the electrooxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid and the electroreduction of nitrate to ammonia (NH₃). The open-circuit potential spontaneous experiment shows that more 5-hydroxymethylfurfural molecules are adsorbed in the Helmholtz layer of the CuO/Co₃O₄ composite, which certifies that the CuO/Co₃O₄ heterostructure is conducive to the kinetic adsorption of 5-hydroxymethylfurfural. In situ electrochemical impedance spectroscopy further shows that CuO/Co₃O₄ has faster reaction kinetics and lower reaction potential in oxygen evolution reaction and 5-hydroxymethylfurfural electrocatalytic oxidation. Moreover, CuO/Co₃O₄ also has a good reduction effect on NO₃^-. The ex-situ Raman spectroscopy shows that under the reduction potential, the metal oxide is reduced, and the generated Cu₂O can be used as a new active site for the reaction to promote the electrocatalytic conversion of NO₃^- to NH₃ synthesis. This work provides valuable guidance for the synthesis of value-added chemicals by 5-hydroxymethylfurfural electrocatalytic oxidation coupled with NO₃^- while efficiently producing NH₃.

In response to the ongoing energy crisis, advancing the field of electrocatalytic water splitting is of utmost significance, necessitating the urgent development of high-performance, cost-effective, and durable hydrogen evolution reaction catalysts. But the generated gas bubble adherence to the electrode surface and sluggish separation contribute to significant energy loss, primarily due to the insufficient exposure of active sites, thus substantially hindering electrochemical performance. Here, we successfully developed a superaerophobic catalytic electrode by loading phosphorus-doped nickel metal (NiP_x) onto various conductive substrates via an electrodeposition method. The electrode exhibits a unique surface structure, characterized by prominent surface fissures, which not only exposes additional active sites but also endows the electrode with superaerophobic properties. The NiP_x/Ti electrode demonstrates superior electrocatalytic activity for hydrogen evolution reaction, significantly outperforming a platinum plate, displaying an overpotential of mere 216 mV to achieve a current density of -500 mA cm^-2 in 1 M KOH. Furthermore, the NiP_x/Ti electrode manifests outstanding durability and robustness during continuous electrolysis, maintaining stability at a current density of -10 mA cm^-2 over a duration of 2000 h. Owing to the straightforward and scalable preparation methods, this highly efficient and stable NiP_x/Ti electrocatalyst offers a novel strategy for the development of industrial water electrolysis.

Perovskite solar cells have emerged as a promising technology for renewable energy generation. However, the successful integration of perovskite solar cells with energy storage devices to establish high-efficiency and long-term stable photorechargeable systems remains a persistent challenge. Issues such as electrical mismatch and restricted integration levels contribute to elevated internal resistance, leading to suboptimal overall efficiency (η_overall) within photorechargeable systems. Additionally, the compatibility of perovskite solar cells with electrolytes from energy storage devices poses another significant concern regarding their stability. To address these limitations, we demonstrate a highly integrated photorechargeable system that combines perovskite solar cells with a solid-state zinc-ion hybrid capacitor using a streamlined process. Our study employs a novel ultraviolet-cured ionogel electrolyte to prevent moisture-induced degradation of the perovskite layer in integrated photorechargeable system, enabling perovskite solar cells to achieve maximum power conversion efficiencies and facilitating the monolithic design of the system with minimal energy loss. By precisely matching voltages between the two modules and leveraging the superior energy storage efficiency, our integrated photorechargeable system achieves a remarkable η_overall of 10.01% while maintaining excellent cycling stability. This innovative design and the comprehensive investigations of the dynamic photocharging process in monolithic systems, not only offer a reliable and enduring power source but also provide guidelines for future development of self-power off-grid electronics.

To achieve high-energy-density and safe lithium-metal batteries (LMBs), solid-state electrolytes (SSEs) that exhibit fast Li-ion conductivity and good stability against lithium metal are of great importance. This study presents a systematic exploration of selenide-based materials as potential SSE candidates. Initially, Li₈SeN₂ and Li₇PSe₆ were selected from 25 ternary selenides based on their ability to form stable interfaces with lithium metal. Subsequently, their favorable electronic insulation and mechanical properties were verified. Furthermore, extensive theoretical investigations were conducted to elucidate the fundamental mechanisms underlying Li-ion migration in Li₈SeN₂, Li₇PSe₆, and derived Li₆PSe₅X (X = Cl, Br, I). Notably, the highly favorable Li-ion conduction mechanism of vacancy diffusion was identified in Li₆PSe₅Cl and Li₇PSe₆, which exhibited remarkably low activation energies of 0.21 and 0.23 eV, and conductivity values of 3.85 × 10^-2 and 2.47 × 10^-2 S cm^-1 at 300 K, respectively. In contrast, Li-ion migration in Li₈SeN₂ was found to occur via a substitution mechanism with a significant diffusion energy barrier, resulting in a high activation energy and low Li-ion conductivity of 0.54 eV and 3.6 × 10^-6 S cm^-1, respectively. Throughout this study, it was found that the ab initio molecular dynamics and nudged elastic band methods are complementary in revealing the Li-ion conduction mechanisms. Utilizing both methods proved to be efficient, as relying on only one of them would be insufficient. The discoveries made and methodology presented in this work lay a solid foundation and provide valuable insights for future research on SSEs for LMBs.

Direct synthesis of layer-tunable and transfer-free graphene on technologically important substrates is highly valued for various electronics and device applications. State of the art in the field is currently a two-step process: a high-quality graphene layer synthesis on metal substrate through chemical vapor deposition (CVD) followed by delicate layer transfer onto device-relevant substrates. Here, we report a novel synthesis approach combining ion implantation for a precise graphene layer control and dual-metal smart Janus substrate for a diffusion-limiting graphene formation to directly synthesize large area, high quality, and layer-tunable graphene films on arbitrary substrates without the post-synthesis layer transfer process. Carbon (C) ion implantation was performed on Cu–Ni film deposited on a variety of device-relevant substrates. A well-controlled number of layers of graphene, primarily monolayer and bilayer, is precisely controlled by the equivalent fluence of the implanted C-atoms (1 monolayer ∼4 × 10¹⁵ C-atoms/cm²). Upon thermal annealing to promote Cu-Ni alloying, the pre-implanted C-atoms in the Ni layer are pushed toward the Ni/substrate interface by the top Cu layer due to the poor C-solubility in Cu. As a result, the expelled C-atoms precipitate into a graphene structure at the interface facilitated by the Cu-like alloy catalysis. After removing the alloyed Cu-like surface layer, the layer-tunable graphene on the desired substrate is directly realized. The layer-selectivity, high quality, and uniformity of the graphene films are not only confirmed with detailed characterizations using a suite of surface analysis techniques but more importantly are successfully demonstrated by the excellent properties and performance of several devices directly fabricated from these graphene films. Molecular dynamics (MD) simulations using the reactive force field (ReaxFF) were performed to elucidate the graphene formation mechanisms in this novel synthesis approach. With the wide use of ion implantation technology in the microelectronics industry, this novel graphene synthesis approach with precise layer-tunability and transfer-free processing has the promise to advance efficient graphene-device manufacturing and expedite their versatile applications in many fields.

Electrocatalytic reduction of CO₂ into high energy-density fuels and value-added chemicals under mild conditions can promote the sustainable cycle of carbon and decrease current energy and environmental problems. Constructing electrocatalyst with high activity, selectivity, stability, and low cost is really matter to realize industrial application of electrocatalytic CO₂ reduction (ECR). Metal–nitrogen–carbon (M–N–C), especially Ni–N–C, display excellent performance, such as nearly 100% CO selectivity, high current density, outstanding tolerance, etc., which is considered to possess broad application prospects. Based on the current research status, starting from the mechanism of ECR and the existence form of Ni active species, the latest research progress of Ni–N–C electrocatalysts in CO₂ electroreduction is systematically summarized. An overview is emphatically interpreted on the regulatory strategies for activity optimization over Ni–N–C, including N coordination modulation, vacancy defects construction, morphology design, surface modification, heteroatom activation, and bimetallic cooperation. Finally, some urgent problems and future prospects on designing Ni–N–C catalysts for ECR are discussed. This review aims to provide the guidance for the design and development of Ni–N–C catalysts with practical application.

Metal-covalent organic frameworks (MCOF) as a bridge between covalent organic framework (COF) and metal organic framework (MOF) possess the characteristics of open metal sites, structure stability, crystallinity, tunability as well as porosity, but still in its infancy. In this work, a covalent organic framework DT-COF with a keto-enamine structure synthesized from the condensation of 3,3′-dihydroxybiphenyl diamine (DHBD) and triformylphloroglucinol (TFP) was coordinated with Cu²⁺ by a simple post-modification method to a obtain a copper-coordinated metal-covalent organic framework of Cu-DT COF. The isomerization from a keto-enamine structure of DT-COF to a enol-imine structure of Cu-DT COF is induced due to the coordination interaction of Cu²⁺. The structure change of Cu-DT COF induces the change of the electron distribution in the Cu-DT COF, which greatly promotes the activation and deep Li-storage behavior of the COF skeleton. As anode material for lithium-ion batteries (LIBs), Cu-DT COF exhibits greatly improved electrochemical performance, retaining the specific capacities of 760 mAh g^-1 after 200 cycles and 505 mAh g^-1 after 500 cycles at a current density of 0.5 A g^-1. The preliminary lithium storage mechanism studies indicate that Cu²⁺ is also involved in the lithium storage process. A possible mechanism for Cu-DT COF was proposed on the basis of FT-IR, XPS, EPR characterization and electrochemical analysis. This work enlightens a novel strategy to improve the energy storage performance of COF and promotes the application of COF and MCOF in LIBs.

Aluminum (Al)-ion batteries have emerged as a potential alternative to conventional ion batteries that rely on less abundant and costly materials like lithium. Nonetheless, given the nascent stage of advancement in Al-ion batteries (AIBs), attaining electrode materials that can leverage both intercalation capacity and structural stability remains challenging. Herein, we demonstrate a C₃N₄-derived layered N,S heteroatom–doped carbon, obtained at different pyrolysis temperatures, as a cathode material for AIBs, encompassing the diffusion–controlled intercalation and surface-induced capacity with ultrahigh reversibility. The developed layered N,S-doped corbon (N,S-C) cathode, synthesized at 900 °C, delivers a specific capacity of 330 mAh g^–1 with a relatively high coulombic efficiency of ∼85% after 500 cycles under a current density of 0.5 A g^-1. Owing to its reinforced adsorption capability and enlarged interlayer spacing by doping N and S heteroatoms, the N,S-C900 cathode demonstrates outstanding energy storage capacity with excellent rate performance (61 mAh g^–1 at 20 A g^–1) and ultrahigh reversibility (90 mAh g^–1 at 5 A g^–1 after 10 000 cycles).

Developing anode materials with high specific capacity and cycling stability is vital for improving thin-film lithium-ion batteries. Thin-film zinc oxide (ZnO) holds promise due to its high specific capacity, but it suffers from volume changes and structural stress during cycling, leading to poor battery performance. In this research, we ingeniously combined polytetrafluoroethylene (PTFE) with ZnO using a radio frequency (RF) magnetron co-sputtering method, ensuring a strong bond in the thin-film composite electrode. PTFE effectively reduced stress on the active material and mitigated volume change effects during Li⁺ ion intercalation and deintercalation. The composite thin films are thoroughly characterized using advanced techniques such as X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy for investigating correlations between material properties and electrochemical behaviors. Notably, the ZnO/PTFE thin-film electrode demonstrated an impressive specific capacity of 1305 mAh g^–1 (=7116 mAh cm^–3) at a 0.5C rate and a remarkable capacity retention of 82% from the 1st to the 100th cycle, surpassing the bare ZnO thin film (50%). This study provides valuable insights into using binders to stabilize active materials in thin-film batteries, enhancing battery performance.

The separator is an essential component of sodium-ion batteries (SIBs) to determine their electrochemical performances. However, the separator with high mechanical strength, good electrolyte wettability and excellent electrochemical performance remains an open challenge. Herein, a new separator consisting of amphoteric nanofibers with abundant functional groups was fabricated through supramolecular assembly of natural polymers for SIB. The uniform nanoporous structure, remarkable mechanical properties and abundant functional groups (e.g. –COOH, –NH₂ and –OH) endow the separator with lower dissolution activation energy and higher ion migration numbers. These metrics enable the separator to lower the barrier for desolvation of Na⁺, accelerate the migration of Na⁺, and generate more stable solid electrolyte interphase (SEI) and cathode electrolyte interphase (CEI). The battery assembled with the amphoteric nanofiber separator shows higher specific capacity and better stability than that assembled with glass fiber (GF) separator.

The ideal composite electrolyte for the pursued safe and high-energy-density lithium metal batteries (LMBs) is expected to demonstrate peculiarity of superior bulk conductivity, low interfacial resistances, and good compatibility against both Li-metal anode and high-voltage cathode. There is no composite electrolyte to synchronously meet all these requirements yet, and the battery performance is inhibited by the absence of effective electrolyte design. Here we report a unique “concentrated ionogel-in-ceramic” silanization composite electrolyte (SCE) and validate an electrolyte design strategy based on the coupling of high-content silane-conditioning garnet and concentrated ionogel that builds well-percolated Li⁺ transport pathways and tackles the interface issues to respond all the aforementioned requirements. It is revealed that the silane conditioning enables the uniform dispersion of garnet nanoparticles at high content (70 wt%) and forms mixed-lithiophobic-conductive LiF-Li₃N solid electrolyte interphase. Notably, the yielding SCE delivers an ultrahigh ionic conductivity of 1.76 × 10^-3 S cm^-1 at 25 °C, an extremely low Li-metal/electrolyte interfacial area-specific resistance of 13 Ω cm², and a distinctly excellent long-term 1200 cycling without any capacity decay in 4.3 V Li‖LiNi_0.5Co_0.2Mn_0.3O₂ (NCM523) quasi-solid-state LMB. This composite electrolyte design strategy can be extended to other quasi–/solid-state LMBs.

In a unified regenerative fuel cell (URFC) or reversible fuel cell, the oxygen bifunctional catalyst must switch reversibly between the oxygen reduction reaction (ORR), fuel cell mode, and the oxygen evolution reaction (OER), electrolyzer mode. However, it is often unclear what effect alternating between ORR and OER has on the electrochemical behavior and physiochemical properties of the catalyst. Herein, operando X-ray absorption spectroscopy (XAS) is utilized to monitor the continuous and dynamic evolution of the Co, Mn, and Fe oxidation states of perovskite catalysts Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ (BSCF) and La_0.4Sr_0.6MnO_3-δ (LSM), while the potential is oscillated between reducing and oxidizing potentials with cyclic voltammetry. The results reveal the importance of investigating bifunctional catalysts by alternating between fuel cell and electrolyzer operation and highlight the limitations and challenges of bifunctional catalysts. It is shown that the requirements for ORR and OER performance are divergent and that the oxidative potentials of OER are detrimental to ORR activity. These findings are used to give guidelines for future bifunctional catalyst design. Additionally, it is demonstrated how sunlight can be used to reactivate the ORR activity of LSM after rigorous cycling.

Lithium-ion batteries (LIBs) play a pivotal role in today’s society, with widespread applications in portable electronics, electric vehicles, and smart grids. Commercial LIBs predominantly utilize graphite anodes due to their high energy density and cost-effectiveness. Graphite anodes face challenges, however, in extreme safety-demanding situations, such as airplanes and passenger ships. The lithiation of graphite can potentially form lithium dendrites at low temperatures, causing short circuits. Additionally, the dissolution of the solid-electrolyte-interphase on graphite surfaces at high temperatures can lead to intense reactions with the electrolyte, initiating thermal runaway. This review introduces two promising high-safety anode materials, Li₄Ti₅O₁₂ and TiNb₂O₇. Both materials exhibit low tendencies towards lithium dendrite formation and have high onset temperatures for reactions with the electrolyte, resulting in reduced heat generation and significantly lower probabilities of thermal runaway. Li₄Ti₅O₁₂ and TiNb₂O₇ offer enhanced safety characteristics compared to graphite, making them suitable for applications with stringent safety requirements. This review provides a comprehensive overview of Li₄Ti₅O₁₂ and TiNb₂O₇, focusing on their material properties and practical applicability. It aims to contribute to the understanding and development of high-safety anode materials for advanced LIBs, addressing the challenges and opportunities associated with their implementation in real-world applications.

Hydrogen spillover effect has recently garnered a lot of attention in the field of electrocatalytic hydrogen evolution reactions. A new avenue for understanding the dynamic behavior of atomic migration in which hydrogen atoms moving on a catalyst surface was opened up by the setup of the word “hydrogen spillover.” However, there is currently a dearth of thorough knowledge regarding the hydrogen spillover effect. Currently, the advancement of sophisticated characterization procedures offers progressively useful information to enhance our grasp of the hydrogen spillover effect. The understanding of material fabrication for hydrogen spillover effect has erupted. Considering these factors, we made an effort to review most of the articles published on the hydrogen spillover effect and carefully analyzed the aspect of material fabrication. All of our attention has been directed toward the molecular pathway that leads to improve hydrogen evolution reactions performance. In addition, we have attempted to elucidate the spillover paths through the utilization of DFT calculations. Furthermore, we provide some preliminary research suggestions and highlight the opportunities and obstacles that are still to be confronted in this study area.