It is crucial to achieve high energy density and fast charging simultaneously for automotive lithium-ion batteries. The nickel-rich layered oxide LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) cathode enables high energy density due to its high theoretical capacity and high working voltage. However, the fast charging performance is compromised because the electrode-electrolyte interface kinetics deteriorates when working at high voltage. A new approach is proposed to solve this dilemma, where [60] Fullerenoacetic acid (C₆₀-COOH) is used to tune the interface structure of the NCM811. The carboxylic acid functional group ensures preferential deposition of C₆₀ onto the NCM811 surface through the reaction with the surface residual alkaline species/transition metals. An electronic and ionic conductive thin coating layer is formed on the NCM811 surface, which inhibits electrolyte decomposition and facilitates formation of high voltage stable cathode electrolyte interface. With 0.50 wt.‰ of C₆₀-COOH, the NCM811 cathode exhibits significantly improved electrochemical performance at 4.6 V in terms of reversible capacity, and capacity retention ratio, where an exceptional fast charging/discharging performance at 10 C is demonstrated as well. This work is of great significance for promoting high energy density and fast charging automotive lithium-ion batteries.

Lignin-based guaiacol and its derivatives can be hydrogenated to synthesize 2-methoxycyclohexanols (2-MCHs), widely used in the pharmaceutical industry, while the efficient catalytic conversion of guaiacols into 2-MCHs is challenging due to the interference of the side reaction of C_Ar-OCH₃ bond cleavage. In this work, highly selective hydrogenation of various guaiacyl lignin-derived phenols to 2-MCHs (yields of 86%-97%) was realized over a single-atom Ru-based catalyst (Ru₁/o-CeO₂-ov) that preferentially exposes the CeO₂(111) plane and has abundant oxygen vacancies. Control experiments and mechanism studies expounded that Ru-O-Ce is the active site for hydrogenation of aromatic ring in guaiacols, and the exposed (111) plane and abundant oxygen vacancies of ceria can reduce the activation energy of aromatic ring hydrogenation, thereby enabling guaiacols to generate the corresponding hydrogenated products with high selectivity. Response surface optimization experiments indicated that temperature and time have relatively more significant effects on the 2-MCH yield. Moreover, the Ru₁/o-CeO₂-ov catalyst exhibited excellent reusability, and was extensively applicable to the hydrogenative dearomatization of different types of lignin-derived phenols, providing a unique solution for upgrading biomass feedstock into specific structural chemicals.

Emerging Zinc-ion hybrid supercapacitors (ZHSCs) are being vigorously pursued due to their sustainability, economic efficiency, high safety and excellent theoretical electrochemical properties. As a significant element in the advancement of ZHSCs, carbonaceous materials can be utilized for fabricating the cathode and electrolyte and protecting the Zinc anode. Despite advancements, challenges notably persist in the form of unsatisfactory rate performance, scarcity of active sites, and undesirable cycling stability within carbonaceous cathodes. Here, this mini-review thoroughly expounds on the recent progress of carbonaceous materials with different dimensions and the corresponding synthesis strategies. The complexity of the structure, morphology, and relevant properties of sophisticated carbonaceous materials employed in contemporary devices is discussed. Besides, we elaborate on the strategies for modifying these materials to achieve optimal characteristics. Finally, the assessment of the existing challenges and prospects for carbonaceous materials within ZHSCs is explored. We anticipate that the insights presented herein can pave the way for developing carbonaceous materials, heading toward future-generation energy storage devices.

Room-temperature sodium-sulfur (RT Na-S) batteries are potential candidates for next-generation energy storage systems because of low-cost resources, high theoretical capacity, and high energy density. However, their commercialization is hindered by the inherent shuttle effect, insulation of sulfur, and slow catalytic conversion. This study proposes a novel approach involving the design of a C/CoFe alloy catalyst coupled with Ti₃C₂T_x MXene substrate (C/CoFe-MXene) as a three-dimensional porous conductive sulfur host. Polysulfide adsorption/catalytic experiments and density functional theory calculation confirmed the excellent affinity and strong catalytic conversion ability of the C/CoFe-MXene composite for polysulfides. The heterostructure formed between the CoFe alloy and the MXene substrate promotes Na⁺ transport and accelerates reaction kinetics of sulfur species. Consequently, the assembled RT Na-S batteries with a C/CoFe-MXene sulfur host (2.0 mg cm^-2) deliver a high initial specific capacity of 572 mAh g^-1 at 1 C. Even at 5 C, the battery achieves ultralong-term cycling over 5,400 cycles with a capacity retention rate of 61.9%, corresponding to a slow capacity fading rate of 0.0089% per cycle, demonstrating outstanding high-rate tolerance. This work provides new insights into the preparation of three-dimensional porous sulfur cathodes with high specific surface area and excellent catalytic activity using catalysts loaded on MXene substrates in RT Na-S batteries.

To improve electrode performance, understanding the complex changes within electrodes when working is vital. The lithiation process in graphite electrodes involves the influx of Li ions from the separator and electrons from the current collector, coupled with materials’ hindrance for charged particle movement, leading to reaction extent heterogeneity. Since capacity is the cumulative effect of current density, real-time monitoring of current density to investigate reaction pathways in different sections of the electrode can enhance our knowledge of the pattern of heterogeneity as the rate increases and progression of reaction extent heterogeneity, aiding in developing mitigation strategies. This study used a pouch cell with a multilayer graphite electrode to monitor current density in real time, revealing patterns associated with increasing rates and the progression of reaction extent heterogeneity inside graphite. The results show that with rate increasing, the current density inside graphite becomes more heterogeneous, leading to more severe reaction extent heterogeneity. Besides, it is shown that heterogeneous current density leads to lithiation of top part in graphite. The resulting additional capacity released from lithium deposition will compensate for the unused capacity of the remaining layers. Consequently, for the graphite, safety has been weakened and lithium inventory has decreased while total capacity remains almost unaffected during the first lithiation.

Solid electrolytes provide improved safety, greater electrochemical and thermal stability, and better compatibility with high-energy materials than liquid electrolytes. Compared to crystalline solid electrolytes, amorphous solid electrolytes offer reduced grain boundary resistance, enhanced processability, isotropic ionic conductivity and superior mechanical properties. Herein, the impacts of varying high-energy ball milling intensities on the degree of amorphization of amorphous 1.6Li₂O-TaCl₅ oxychloride and thus its ionic conductivity are investigated. It is shown that the ionic conductivity of amorphous 1.6Li₂O-TaCl₅ can reach as high as 8.30 × 10^-3 S/cm at room temperature by increasing the degree of amorphization. Furthermore, the sample exhibiting the highest ionic conductivity also releases the largest stored enthalpy upon heating, indicating that structural defects in amorphous 1.6Li₂O-TaCl₅ materials play a crucial role in enhancing their Li-ion conductivities. This discovery opens the door for boosting the ionic conductivities of other amorphous electrolytes in the future by increasing the degree of amorphization.

The development of functional interlayers to effectively anchor lithium polysulfide and enhance the integrity of sulfur cathodes in lithium-sulfur (Li-S) batteries has received significant global consideration. However, identifying an interlayer that is both highly conductive and structurally robust remains a major challenge. This study presents the synthesis of three-dimensional nitrogen-doped carbon microspheres embedded with bismuth selenide nanocrystals (referred to as “three-dimensional (3D) Bi₂Se₃@N-C” microspheres) and evaluates their role as a polysulfide barrier for enhanced Li-S battery performance. The embedded Bi₂Se₃ nanocrystals within the microspheres provide numerous active spots for chemical captivity and electrocatalytic transformation of lithium polysulfide species. Moreover, the N-doped carbon framework facilitates speedy transfer of charge moieties, resulting in faster redox activity. Correspondingly, cells paired with 3D Bi₂Se₃@N-C microsphere modified separators exhibit excellent rate capability (297 mA h g^-1 at 2.0 C-rate) and prolonged stable cycling performance at different C-rates (863 mA h g^-1 after 100 cycles at 0.1 C, 440 mA h g^-1 after 200 cycles at 0.5 C, and 219 mA h g^-1 after 500 cycles at 2.0 C). The cell demonstrates satisfactory cycling performance retaining 57% of its capacity after 200 cycles when the active material loading was raised to 3.5 mg cm^-2, confirming the practical feasibility of the prepared nanostructure. The detailed physical and electrochemical results presented in this study offer valuable perceptions for the expansion of structurally superior, conductive, and easily scalable nanostructures for various energy storage demands.

Owing to the advantages of low cost, rich resources, and intrinsic safety, aqueous Zn-ion batteries have attracted broad attention as the promising energy storage technology for large-scale smart grids. The cathodes for aqueous Zn-ion batteries have developed rapidly, including Mn-based cathodes, V-based cathodes, and halogen cathodes. High specific capacity and long cycling lifespan have been achieved. However, when the mass loading for cathode materials is scaled up to the practical level, the cycling stability and rate property of aqueous Zn-ion batteries are very unsatisfactory. Therefore, in this review, we deeply analyze the key issues that limit the electrochemical performance of high-loading cathodes for aqueous Zn-ion batteries. Subsequently, we comprehensively summarize the effective solutions to the above issues, including (1) rational binder design, (2) three-dimensional cathode design, (3) cathode material structural optimization, and (4) interface engineering for Zn anodes. Finally, we give a critical perspective from commercial application for the future development of high-loading cathodes for high-energy-density aqueous Zn-ion batteries.

The nickel-rich NMC₉₅₅ (LiNi_0.90Mn_0.05Co_0.05O₂) cathode, with minimal cobalt, is the zenith of LiNi_xMn_yCo_1-x-yO₂ (NMC) technology but faces structural and thermal stability challenges, losing an average of 15% of its capacity in the first discharge. Here, by selecting appropriate materials and synthesis methods in an all-solid-state battery cell, this challenge is effectively mitigated. A sustainable fabrication of the LiNMC₉₅₅ positive electrode, excluding poly(vinylidene fluoride) (PVDF) and using styrene-butadiene rubber, demonstrates high retention in all-solid-state cells, without additional interlayers or pressure, at room temperature. To prevent oxygen release, spurious phase formation, and magnetic frustration, simulations determined optimal cycling thresholds and curve morphologies for a Li⁰/Li₆PS₅Cl/NMC₉₅₅ cell by “following the electrons”. This optimized routine ensures prolonged cycle life and performance demonstrated by sheet resistance/Hall effect, Scanning Electron Microscopy/Energy-Dispersive X-ray Spectroscopy (SEM/EDX), Atomic Force Microscopy/Scanning Kelvin Probe Microscopy, Time-of-Flight Secondary Ion Mass Spectrometry, Raman, calorimetry, and electrochemical analyses. The tailored preparation method and cycling regimen enabled the fabrication of a high-performance cathode, achieving capacities exceeding 110-120 mAh.g^-1 at C discharging C-rate, after 200 cycles, with a self-recovering component shifting performance to theoretical capacities (192 mAh.g^-1), emphasizing the cathode's pivotal role in all-solid-state performance.

Due to its adsorption on graphite and superior thickening properties, carboxymethylcellulose (CMC) is widely used as a dispersant and rheology modifier in water-based anode slurries for lithium-ion batteries. CMC also provides cohesion to the dry anode layer but exhibits poor adhesion to the copper foil necessitating the addition of styrene-butadiene rubber (SBR) as an adhesion promoter. High adhesion between the electrode layer and the current collector is crucial in electrode fabrication, especially for electrodes with higher mass loadings. In this work, we investigate how a polymeric binder, originally intended as a thickening and dispersing agent, can significantly affect the adhesive strength between the anode layer and the current collector. Our results reveal that CMC, by adsorbing onto active material particles (graphite, micro-silicon or nano-silicon), indirectly influences the anode adhesion. The adsorbed CMC layer hinders the direct binding of SBR to the active material particles, thereby creating the weakest link between the active layer and the current collector. This effect is more pronounced the higher the CMC molecular weight. Moreover, we could show that graphite-nano-silicon composite anodes exhibit a significantly reduced adhesion to the copper foil despite a low adsorption of CMC on nano-silicon, since a large fraction of SBR particles are trapped in the porous, micron-sized nano-silicon aggregates. Our findings highlight the importance of considering thickener adsorption on active material particles within electrode design, as a factor that exerts an indirect, albeit significant, influence on anode adhesion.

Although lithium-ion batteries are emerging as one of the leading energy storage technologies due to their high energy density, high specific capacity, and fast charging speed, major challenges remain regarding the use of liquid electrolytes. These electrolytes directly affect the safety and durability of the batteries. While alternative materials such as rigid solid-state electrolytes have been developed to improve safety, they often suffer from poor ionic conductivity and inadequate interfacial contact with the electrodes. These issues hinder the production and widespread application of lithium-ion batteries. To overcome these disadvantages, quasi-solid-state electrolytes, which include both liquid and solid components, have been extensively researched. Among these, metal-organic frameworks (MOFs) with diverse morphological designs and porous structures are considered promising materials for the fabrication of high-performance quasi-solid-state electrolytes. This review summarizes recent research on MOF-based separators for lithium metal batteries, including native MOFs, MOF composites, and MOF derivatives. The fabrication processes and mechanisms for enhancing the electrochemical performance of each separator material are discussed. Furthermore, the prospects of this promising material for lithium metal batteries are provided.

Silicon (Si) holds promise as an anode material for next-generation lithium-ion batteries due to its high theoretical capacity. However, practical applications are impeded by structural damage from volume expansion. Here, we designed a novel Si/CNFs/C anode by integrating mesoporous Si particles, carbon nanofibers (CNFs), and carbon quantum dots into a three-dimensional (3D) architecture via a one-step magnesiothermic reduction process. This design significantly enhances both electron and ion conductivity, alleviates the volume expansion of Si particles, and ensures mechanical stability during battery operation. Consequently, batteries with the Si/CNFs/C anode exhibit a reversible capacity of 1,172.4 mAh g^-1 after 200 cycles at 0.1 A g^-1 and maintain 1,107.7 mAh g^-1 after 1,000 cycles at 1 A g^-1. Notably, after 1,000 cycles at a high current density of 1 A g^-1, the capacity remains nearly comparable to that after 100 cycles at 0.1 A g^-1, attributed to significant pseudocapacitive characteristics that facilitate high performance under elevated current densities. Furthermore, we employed distribution of relaxation times analysis alongside other electrochemical techniques to investigate changes in ion transport pathways and the evolving role of Si in the energy storage process. Our design and analysis provide valuable insights for optimizing 3D conductive architectures and understanding the dynamic electrochemical mechanisms of Si-based anodes, advancing the development of high-performance lithium-ion batteries.

Enhancing the power conversion efficiency (PCE) of solar cells is a constant and essential endeavor to advance the utilization of renewable electricity, especially for space and planetary exploration. The challenge of significantly enhancing the PCE of solar cells is considerable. This report examines the impact of temperature on the PCE of monocrystalline single-junction GaAs solar cells under 450/520/635 nm lasers and achieves ~40% increase over the PCE at room temperature when the temperature is reduced from 300 K to 160 K. The notable enhancement in PCE can be attributed to suppressing the lattice atoms’ thermal oscillations and mitigating thermal loss. Below 160 K, however, the radiative recombination produces many low-energy photons, which cannot overcome the GaAs bandgap, resulting in energy loss and a sharp PCE decrease. In addition, the onset of carrier freeze-out effects restricts further increase in PCE. Our study elucidates the optimal operating temperature of GaAs solar cells, paving the way for designing an ultra-high PCE energy supply for planet probes such as the Moon and Mars, where the temperature exceeds 160 K.

The green synthesis of hydrogen through electrochemical water splitting has been severely limited by the slow kinetics of the anodic oxygen evolution reaction (OER). However, the current benchmark electrocatalysts are still based on precious metals. Therefore, developing low-cost and highly efficient OER electrocatalysts is of great importance. Here, we design nanoscale multicomponent metal flakes with a crystalline/amorphous structure (ac-FeCoNiMo) via a simple sol-gel strategy to enhance OER performance. By engineering the structure through a high-valence Mo doping strategy, we successfully develop ac-FeCoNiMo with a unique architecture featuring boundary-rich regions, modulated Fe/Co species, defects, and enlarged metal-O bonds. As a result, the optimized ac-FeCoNiMo exhibits excellent electrochemical OER performance, achieving low overpotentials of 222 mV and 253 mV to reach current densities of 20 mA cm^-2 and 100 mA cm^-2, respectively, along with outstanding stability. Mechanistic investigations reveal that ac-FeCoNiMo follows the Lattice Oxygen Mediated mechanism during the OER process. This behavior is likely due to the induced weakening of metal-oxygen bonds, resulting from the expanded M-O-M (M = metal) units and the formation of abundant boundary-rich regions. This study paves the way for the development of highly efficient multi-element electrocatalysts.

Energy-efficient water electrolysis is one of the most promising techniques for generating green hydrogen as a carbon-free energy source. As a half-reaction of water splitting, the oxygen evolution reaction is kinetically sluggish, leading to large thermodynamic potential gaps compared to the hydrogen evolution reaction. In terms of cost-effective hydrogen generation, mitigating this overpotential is a challenging obstacle, but it remains a hurdle to overcome. It is necessary to advance energy-saving hydrogen production by substituting with an oxygen evolution reaction as a thermodynamically favorable anodic reaction. Additionally, depending on the specific small molecules used for the anodic oxidation reaction, it is possible to reduce environmentally harmful substances and produce value-added chemicals. Nickel-based electrocatalysts have received growing attention for their application in electrochemical reactions due to their affordability, versatility in structural tuning, and ability to function as active sites for bond formation and cleavage. The purpose of this paper is to probe how the morphology, structure, and composition of these catalysts affect the electrocatalyst performance for small molecule oxidation. Explaining these relationships can accelerate the development of sustainable hydrogen production techniques by identifying the design principles of high-performance nickel-based electrocatalysts.

To address the detrimental impact of residual LiOH on the electrochemical performance of LiNi_0.80Co_0.15Al_0.05O₂ (NCA) cathode material, it is imperative to optimize its surface structure. Adding a Li-reactant to react with residual LiOH on the cathode surface not only removes residual LiOH but also forms new surface structure layers. However, this reaction process not only necessitates evaluating the compatibility between the newly formed surface layer and the crystal structure of the NCA cathode material but also requires careful determination of the optimal amount of Li-reactant. Currently, there remains a lack of well-established theoretical guidance for determining the optimal addition amount of lithium reactants. In this study, the quantitative addition of 6,000 ppm Al₂O₃ as a Li-reactant to react with the residual 3,156 ppm LiOH on the NCA surface not only effectively reduces the residual LiOH but also facilitates the formation of a LiAlO₂@NCA heterostructure on the NCA cathode materials. This approach provides a theoretical foundation for the addition of Li-reactant, overcomes the limitations of empirical trial-and-error methods, and achieves quantitative reconstruction of the NCA cathode materials surface structure. Based on an in-depth analysis of the surface structure, first-principles calculations and electrochemical performance tests, the LiAlO₂@NCA heterostructure not only serves as an efficient Li⁺ diffusion channel and reduces the Li⁺ migration energy barrier, but also provides a stable protection of the surface of the cathode material, thereby enhancing its stability and reversibility.

With the growing demand for sustainable energy, hydrogen is recognized as a key clean energy carrier that can stabilize renewable sources such as solar and wind. Traditional hydrogen production primarily relies on grey hydrogen from fossil fuels, which produces significant CO₂ emissions. In contrast, anion exchange membrane water electrolysis (AEMWE) offers a promising pathway to green hydrogen, combining the zero-gap design of proton exchange membrane water electrolysis with the alkaline environment of alkaline water electrolysis. This configuration allows AEMWE to operate with lower KOH concentrations, enhancing safety and enabling cost-effective, earth-abundant transition metals as electrocatalysts for hydrogen and oxygen evolution reactions. Herein, we examine the fundamental principles of AEMWE, including its cell components, reaction mechanisms, and various in situ characterization methods. Additionally, it explores recent progress in optimizing hydrogen and oxygen evolution reaction electrocatalysts, focusing on both precious and non-precious metal designs. We also discuss the prospects for AEMWE in industrial-level applications, underscoring its potential as an efficient, durable, and economically viable technology for sustainable hydrogen production.

Mg₃Sb₂-based n-type Zintl compounds have attracted greater attention for their superior thermoelectric performance, making them a potential candidate for medium-temperature (< 900 K) applications. Herein, this work verifies the p-type Mg_1.8Zn_1.2Sb₂ solid-solution and defect engineering could be the key mechanism to reduce the lattice thermal conductivity (κ_L) for improving the thermoelectric performance. The carrier and phonon transport properties were studied by adding heavy element Ag at Mg-sites of Mg_1.8Zn_1.2Sb₂ solid-solution. As a result, the Ag_0.03Mg_1.77Zn_1.2Sb₂ sample simultaneously obtained the maximum power factor of 456 μW/mK² via band convergence and defect engineering, which led to reduced thermal conductivity of 0.56 W/mK at 753 K by the strengthening of multiscale phonon scattering. In addition, optimized carrier density and thermal conductivity resulting in a maximum figure of merit (zT) of 0.5 at 753 K has been obtained for Ag_0.03Mg_1.77Zn_1.2Sb₂, which is 285% higher than undoped Mg_1.8Zn_1.2Sb₂. This work demonstrates that heavy element substitution induces band convergence and that defect engineering leads to simultaneous improvement in thermoelectric transport properties of p-type Mg_1.8Zn_1.2Sb₂.

This study evaluates the performance and environmental impact of thermoelectric generators (TEGs) by analyzing various thermoelectric materials and system geometries. A comprehensive life cycle assessment is conducted to quantify the embodied energy and carbon emissions associated with different materials. The study employs particle swarm optimization to optimize TEG geometry, aiming to enhance power output while minimizing environmental impact. The results demonstrate that material selection significantly influences both energy conversion efficiency and sustainability. Specifically, PbTe-based TEGs achieve the highest power output, whereas SiGe-based modules exhibit the highest environmental footprint. Through optimization, an 80% increase in power output is achieved for certain configurations, alongside a reduction in CO₂ emissions. Key findings highlight PbTe-based TEGs as the most efficient energy converters, while Bi₂Te₃-based modules strike a balance between performance and sustainability. In contrast, SiGe-based TEGs have the highest environmental footprint due to their high embodied energy. Additionally, the study reveals that optimizing the number of thermocouples and leg dimensions significantly improves energy conversion efficiency and reduces carbon emissions. These findings provide valuable insights for designing next-generation TEG systems that effectively balance performance and environmental responsibility.

The burgeoning field of protonic ceramic fuel cells (PCFCs) is characterized by significant scientific and technological advancements, particularly with the incorporation of BaZr_0.1Ce_0.7Y_0.2O_3-δ (BZCY) as a proton-conducting electrolyte. In the modern energy materials field, the challenge is not only developing new materials but also understanding new mechanisms and gaining an in-depth understanding of their interaction with energy devices. To drive significant advances, it is crucial to address both material-specific challenges and device-level innovations that unlock the full potential of these materials. In this work, we introduced an electrochemical proton injection approach to successfully improve BZCY proton conductivity by an order of magnitude. We also delve into the electrode and interface kinetic processes and their interplay in proton transport within the bulk and grain boundary of the BZCY-electrolyte of PCFCs. These approaches have led to state-of-the-art advances, achieving a proton conductivity of 0.19 S cm^-1 and a device peak power density of 943 mW cm^-2 at 530 °C. Our results demonstrate that the bulk and grain boundary conduction significantly mitigate polarization losses by four to five orders of magnitude, thereby accelerating the kinetic process and further contributing to improved PCFC performance. The appearance of peaks and alterations in relaxation times further illustrate the electrode reactions and proton transport mechanisms. Beyond providing a comprehensive assessment of current technological progress, this article underscores the transformative potential of electrochemical processes in PCFCs, positioning them as a cornerstone in the quest for sustainable and clean energy technologies.