A heterometallic single-source molecular precursor Li₂Mn₂(tbaoac)₆ (1, tbaoac = tert-butyl acetoacetato) has been specifically designed to achieve the lowest decomposition temperature and a clean conversion to mixed-metal oxides. The crystal structure of this tetranuclear molecule was determined by single crystal X-ray diffraction, and the retention of heterometallic structure in solution and in the gas phase was confirmed by nuclear magnetic resonance spectroscopy and mass spectrometry, respectively. Thermal decomposition of this precursor at the temperatures as low as 310 ^oC resulted in a new metastable oxide phase formulated as lithium-rich, oxygen-deficient spinel Li_1.5Mn_1.5O_3.5. This formulation was supported by a comprehensive suite of techniques including thermogravimetric/differential thermal analysis, elemental analysis, inductively coupled mass spectrometry, iodometric titration, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy studies, and Rietveld refinement from powder X-ray diffraction data. Upon heating to about 400 ^oC, this new low-temperature phase disproportionates stoichiometrically, gradually converting to layered Li₂MnO₃ and spinel Li_1+xMn_2-xO₄ (x < 0.5). Further heating to 750 ^oC results in formation of thermodynamically stable Li₂MnO₃ and LiMn₂O₄ phases.

Compositing inorganic ceramics and polymer materials to form all-solid-state electrolytes has been recognized as a feasible approach for the development of all-solid-state batteries. However, polymer-based electrolytes such as polyethylene oxide can electrochemically decompose above 3.9 V (vs. Li⁺/Li), which results in undesirable battery performance. Moreover, dendrite growth can occur on the anode side and further lead to battery short-circuit. This work designs and successfully fabricates stable electrode/electrolyte interfaces on both the composite cathode and anode sides after employing alucone coating layers made through atomic layer deposition. Due to the protection capability of such coating layers, the electrochemical degradation between the composite solid-state electrolytes of Li₇La₃Zr₂O₁₂/polyethylene oxide/lithium bis(trifluoromethane-sulfonyl) imide film and nickel-rich high voltage cathode (LiNi_0.8Mn_0.1Co_0.1O₂) has been obviously suppressed through the significantly improved anti-oxidation capability of the electrolyte. Simultaneously, the alucone coating layer can function as the protective barrier for the lithium metal anode, remarkably suppressing the growth of lithium dendrites. As a result, the obtained all-solid-state batteries with dual electrode/electrolyte interfaces show both high capacity retention and long cycle life, whereas the contrasting battery without protection coating layers shows both the fast capacity decay and micro-shorting behavior. This work presents an effective strategy for constructing more stable electrode/electrolyte interfaces for polymers-based all-solid-state batteries, and also provides a design rationale for materials and structure development in the field of energy storage and conversion.

Thermoelectric (TE) materials can directly convert heat into electrical energy. However, they sustain costly production procedures and batch-to-batch performance variations. Therefore, developing scalable synthetic techniques for large-scale and reproducible quality TE materials is critical for advancing TE technology. This study developed a facile, high throughput, solution-chemical synthetic technique. Microwave-assisted thermolysis process, providing energy-efficient volumetric heating, was used for the synthesis of bismuth and antimony telluride (Bi₂Te₃, Sb₂Te₃). As-made materials were characterized using various techniques, including XRPD, SEM, TEM, XAS, and XPS. Detailed investigation of the local atomic structure of the synthesized Bi₂Te₃ and Sb₂Te₃ powder samples was conducted through synchrotron radiation XAS experiments. Radial distribution functions around the absorbing atoms were reconstructed using reverse Monte Carlo simulations, and effective force constants for the nearest and distant coordination shells were subsequently determined. The observed differences in the effective force constants support high anisotropy of the thermal conductivity in Bi₂Te₃ and Sb₂Te₃ in the directions along and across the quintuple layers in their crystallographic structure. The as-made materials were consolidated via Spark Plasma Sintering to evaluate thermal and electrical transport properties. The sintered TE materials exhibited low thermal conductivity, achieving the highest TE figure-of-merit values of 0.7 (573 K) and 0.9 (523 K) for n-type Bi₂Te₃ and p-type Sb₂Te₃, respectively, shifted significantly to the high-temperature region when compared to earlier reports, highlighting their potential for power generation applications. The scalable, energy- and time-efficient synthetic method developed, along with the demonstration of its potential for TE materials, opens the door for a wider application of these materials with minimal environmental impact.

The pathway to sustainable development and carbon neutrality is contingent upon the development of high-performance porous carbon electrode materials sourced from biomass and industrial waste. The present research introduces an innovative approach for the fabrication of porous carbon, harnessing the collaborative impact of various materials to transform biomass in the form of corncobs and industrial byproduct fly ash into tiered porous carbon characterized by a high specific surface area and excellent functionality, via a simple hydrothermal activation method. This material is particularly well-suited for applications in supercapacitors, lithium-ion batteries, and other energy storage systems. The porous carbon material fabricated from these two waste streams boasts a wealth of pores and an exceptional specific surface area (1,768 m² g^-1), which in turn confers superior electrochemical performance. The material achieves a remarkable specific capacitance of up to 240 F g^-1 (at 1 A g^-1), and demonstrates remarkable properties for lithium storage. Lithium-ion batteries constructed with this material feature an extensive potential range, with an initial specific capacity of 160 mAh g^-1 at 0.1 A g^-1, and a near-perfect coulomb efficiency of approximately 100%. This research uncovers a novel paradigm for the preparation of high-performance porous carbon electrode materials through a low-carbon and environmentally conscious approach. It not only advances the pursuit of carbon neutrality and the realization of carbon peak objectives but also underscores the potential of valorizing biomass and industrial byproducts in the context of cutting-edge energy storage technologies.

Heteroatom-doped carbon materials have shown great potential as anodes for potassium ion hybrid capacitors (PIHCs) thanks to their diverse merits. However, their practicability is limited seriously by sluggish reaction kinetics, short cycling life, and low initial Coulombic efficiency, primarily because of the large ionic radius of K⁺ and undesirable side reactions. Herein, the cost-efficiency low-softening-point coal pitch-derived one-dimensional N/S co-doped carbon nanofibers (N/S-CNFs) are smartly devised as competitive anodes for advanced PIHCs. The as-optimized N/S-CNF anode exhibits a compact morphology, abundant functional groups, and expanded interlayer spacing, rendering an improved initial Coulombic efficiency of 51.5%, high reversible capacities with 328.1 mAh g^-1 at 0.1 A g^-1 and 122.0 mAh g^-1 at 5.0 A g^-1, and robust cycling stability. Theoretical calculations authenticate that N/S co-doping significantly enhances the electric conductivity and K⁺ adsorption capability of fiber anodes. Detailed in-situ X-ray diffraction measurement unveils the intrinsic electrochemical K⁺-storage process of N/S-CNFs. Moreover, the assembled PIHCs depict an extremely high energy density of 106 Wh kg^-1 at 250 W kg^-1, and superb cycling performance with only 0.00016% capacity loss per cycle within 10,000 cycles, highlighting the superb practicality of our fabricated N/S-CNFs for next-generation PIHCs.

The substitution of oxygen evolution reaction with a thermodynamically favorable small molecule oxidation reaction offers a compelling pathway toward efficient and energy-conserving production of clean hydrogen fuel. Here, we report the rational design and synthesis of ultra-long Pt nanowires (NWs) featuring specific crystal facets, which act as bifunctional electrocatalysts for both the hydrogen evolution reaction (HER) and methanol oxidation reaction (MOR) under alkaline electrolyte. Pt NWs exhibited remarkable performance, requiring only 0.61 V to obtain 10 mA cm^-2 when coupling HER with MOR, substantially lower than the 1.76 V demanded for traditional water splitting. The excellent HER and MOR performance could be primarily attributed to the unique one-dimensional structural characteristics, distinctive crystal facets, and increased specific surface area of the Pt NWs. This research underscores the significance of developing bifunctional electrocatalysts, thereby contributing to the ongoing efforts to advance efficient and energy-conserving hydrogen production.

Flexible lithium-ion batteries (FLBs) hold a promising future in the fields of wearable electronic accessories, wearable therapeutic devices, etc. due to their long cycle life, good flexibility, and the transferable experience from traditional rigid lithium-ion batteries. Additionally, electrospinning technology, as an important method of synthesizing fiber materials, has good controllability and shows incomparable advantages in the preparation of fiber-based electrodes. Therefore, this review first discusses the assessment of flexibility and proposes that standardized assessment methods are the foundation for the development of flexible energy storage devices. It then analyzes in detail the principle of electrospinning technology and the impact of various parameters on electrode performance, exploring the controlling of the morphology of fibers by optimizing process parameters. The pivotal role of electrospinning technology in manufacturing FLBs is also discussed, with a particular focus on its contribution to enhancing energy density, cycling stability, and mechanical flexibility in both cathode and anode materials. Overall, the review provides guidance for the development of high-performance FLBs.

With the advancement of wearable and implantable health and medical electronics, biocompatible miniature energy storage devices were developed rapidly. In particular, biocompatible miniature supercapacitors (BMSCs) have the advantages of conventional supercapacitors, such as high-power density, fast charging/discharging rate, and long operating lifetime, as well as strong selectivity of biocompatible materials. They are expected to play an important role in personalized electronic integration systems. Biocompatibility involves the biosafety of materials and relates to the mechanics and geometrical forms. For example, BMSCs should be thin and compact, ensuring ease of portability and comfort for users. They should also be flexible and stretchable to conform to the skin or tissue, providing stable power to electronics even under deformation. Furthermore, biodegradability/bioabsorbability ensures they are both body- and environment-friendly. This review summarizes the recent research progress of BMSCs as wearable and implantable energy storage devices, including the basic requirements and the selection of the components. Additionally, the advanced applications of BMSCs in multifunctional integration systems for real-time health monitoring and medical treatment are introduced, along with the associated challenges and prospects.

Silicon (Si) anodes offer a high specific capacity (> 3,500 mA h g^-1), but severe volume changes during cycling and poor intrinsic conductivity hinder commercialization. Carbon nanotubes (CNTs) are commonly incorporated to improve the electronic conductivity of Si electrodes, but their tendency to aggregate in polar solvent-based slurries leads to non-uniform electrodes. To address this, we synthesize polyacrylamide-grafted CNTs (PAM-g-CNTs) by covalently attaching hydrophilic acrylamide monomers to CNT surfaces. The PAM chains provide steric hindrance that minimizes van der Waals interactions between PAM-g-CNTs and interacts effectively with polar solvents, thus promoting uniform dispersion and forming a stable electron-conductive network within the electrode. Furthermore, PAM-g-CNTs establish hydrogen bonds with Si particles and binder matrices, enhancing the structural integrity of the electrode. The cycling performance of Si half cells incorporating PAM-g-CNTs shows substantial durability after 200 cycles. Moreover, in high-energy-density Si electrode configurations with reduced binder and conductive agent ratios (active material > 70%), PAM-g-CNT-based cells preserved 70% of their initial capacity after 100 cycles, compared to only 20% retention in Super P-based cells. The functionalization of CNTs with hydrophilic PAM thus proves effective in improving dispersion stability and conductivity while reinforcing electrode cohesion. This strategy presents a promising path for developing durable Si anodes for high-energy-density lithium-ion batteries.

Designing a material structure that supports high-capacity and long cycle life in silicon (Si) anodes has been a long-standing challenge for advancing lithium-ion batteries. Yolk-shell design has been considered a most promising design for alleviating the volume expansion feature of Si. However, the significant void between the Si core and the outer shell limits electrical contact and the complete utilization of the Si core and deteriorates the battery performance upon cycling. In this study, we synthesized a bridged multi-layered yolk-shell (MYS) structure design via thermal decomposition of SiH₄ and carbon oxidation in the air atmosphere. This MYS design features a void space to accommodate the volume expansion of the Si core. It includes a carbon bridge (CB) that connects the Si core and outmost shell containing SiO_x/Si/SiO_xwhich improves the electrical contact and lithiation kinetics of the Si core and addresses fundamental issues of low contact between core and shell. As a result, the CB-MYS structure exhibits a high specific capacity of 2,802.2 mAh g^-1, an initial Coulombic efficiency of 90.0%, and maintains structural integrity and stable cycling performance. Hence, we believe the CB-MYS structure is a promising engineering design to enhance the performance of high-capacity alloy anodes for next-generation lithium-ion batteries.

The poor rate performance of hard carbon (HC) in carbonate electrolytes limits its applicability in hybrid capacitors, primarily due to the low working potential and the slow Na⁺ transport kinetics within the potential plateau region. The slow desolvation of Na⁺ at the electrode surface and sluggish transport of Na⁺ through the solid electrolyte interface are the critical factors contributing to this issue. In this study, Co₃O₄ nanoparticles are uniformly self-grown on the HC surface to modulate the surface chemistry of HC. The introduction of Co₃O₄ not only facilitates the desolvation of Na⁺ and reduces internal resistance, but also provides additional active sites for Na⁺ storage as an active material. As a result of these dual effects, HC125@Co₃O₄ (a composite with an optimal Co₃O₄ loading on HC surfaces) exhibits superior rate performance and reversible capacity compared to pure HC. The sodium-ion hybrid capacitor assembled with the HC125@Co₃O₄ anode and activated carbon cathode demonstrates high energy density (129.5 Wh kg^-1 at 583 W kg^-1) and high power density (26.5 Wh kg^-1 at 11,650 W kg^-1), along with excellent long-time cycling stability. This study offers an effective solution to the poor rate performance and slow kinetics of HC in carbonate-based electrolytes, addressing the issue from the perspective of the electrode-electrolyte interface.

Gel-based piezoelectric materials are stretchable, wearable, and environmentally friendly, unlike their conventional solid counterparts. However, designing environment-tolerant, high-performance piezoelectric gels is challenging. Herein, we develop a piezoresponsive stretchable glycerogel (GG), leveraging the cooperative structure-forming effect of cellulose, poly(vinylidene fluoride) (PVDF) and glycerol (a green extremotolerant solvent). The facile inter- and intramolecular cellulose/PVDF interactions within the hydrogen-bonded network of glycerol generate a highly electroactive crystalline β-phase while retaining mechanical integrity. Therefore, the synergy-driven GG is more piezoresponsive than gels fabricated using individual polymers. Despite having a low polymer density (≈16 wt%), the GG exhibits impressive functional attributes such as Young’s modulus (≈12 MPa), tensile strength (≈3 MPa), piezoelectric voltage (92 mV cm^-2), and current output (110 nA cm^-2). Furthermore, it exhibits long-term stability over a wide temperature range (-20 to 80 °C) owing to its robust structural integrity and thermal adaptability. The study findings underscore the viability of preparing high-performance extremotolerant piezoelectric gels for use in next-generation stretchable/wearable piezoelectric sensors and energy devices.

Lithium-sulfur (Li-S) batteries are one of the most promising technologies compared to lithium-ion-based ones, mainly due to their outstanding high energy density (2,567 Wh/kg). Nonetheless, Li-S batteries still face important drawbacks, namely the shuttle effect caused by the polysulfide dissolution into the electrolyte and their escape from the cathode, leading to active material loss and ultimately to the anode passivation. Mitigating this effect is crucial to boost the Li-S technologies at a large scale and the rational design of the separator or interlayer is considered as an effective solution. Metal-Organic Frameworks and related composites have been recently proposed as candidates to selectively capture the polysulfides, due to their tunable structures and compositions and ordered micro- or meso-porosity which can sieve polysulfides through physical barriers or chemical sorption and catalyze polysulfide conversion kinetics. Moreover, once introduced into composite membranes as functional separators and interlayers, this promotes their easy inclusion in Li-S devices. This short review summarizes the recent progress in this field, emphasizing the different types of functional separators and interlayers integrating Metal-Organic Frameworks, and proposes new research directions to optimize these systems.

Seawater electrolysis offers a sustainable solution for hydrogen production by utilizing ocean water as an electrolyte. However, the chlorine evolution reaction (ClER) and the accumulation of magnesium and calcium precipitates pose significant challenges to efficiency and durability. ClER competes with the oxygen evolution reaction, reducing hydrogen output and accelerating electrode degradation, while precipitate formation on the cathode blocks catalytic sites and impairs long-term performance. Anion exchange membrane water electrolyzers tackle these challenges by leveraging alkaline media to suppress ClER and enhance catalyst stability. Recent advances in selective catalysts, protective coatings, and alternative oxidation reactions further improve reaction selectivity and energy efficiency. Additionally, strategies such as surface engineering and pH modulation mitigate precipitate formation, ensuring stable operation. Scaling these innovations into anion exchange membrane water electrolyzer systems demonstrates their potential for industrial-level hydrogen production. By overcoming fundamental challenges and practical barriers, seawater electrolysis advances toward commercial deployment and a sustainable energy future.

Lithium-ion batteries are extensively utilized due to their diverse applications, but their potential risk of thermal runaway leading to fire or even explosion remains a significant challenge to their sustainable development. The simulation of battery thermal runaway is complex, as it involves multiple reaction mechanisms. This study focuses on the interfacial interactions between reducing gases and cathode materials and explores the factors that influence these interactions during gas crosstalk within the battery. Thermogravimetric analysis coupled with differential scanning calorimetry was used to simulate the thermal attack of argon and hydrogen ($ \mathrm{H}_2 $/Ar) mixtures on battery cathode materials to evaluate the chemical impact on the thermal runaway process. Four key material and environmental parameters, (1) cathode atomic composition; (2) hydrogen gas concentration; (3) gas flow rate; and (4) heating rate, were controlled and paired with thermal analysis curves to compile a database of 55 possible cases. Using seven input variables, this database was trained by an artificial neural network model to predict 11 critical degradation temperatures and rates for assessing material stability and safety. With an overall prediction accuracy above 0.73 (test set), we adopted an analytic hierarchy process to establish a novel scoring mechanism for cathode thermal stability. This work provides valuable insights into battery thermal runaway mechanisms and practical guidance for optimizing battery cathode chemistry.

Aqueous Zn-based flow batteries often face issues such as poor reversibility and short lifespan due to irregular Zn deposition and detrimental side reactions. To address these challenges, we developed a zwitterionic gemini additive, N,N′-bis(3-propanesulfonic acid)-3,3′-bipyridinium (SPr-Bpy), to enhance Zn plating/stripping behavior and optimize the Zn²⁺ solvation structure. The dual sulfonate groups influence the Zn²⁺ solvation shell and anchor SPr-Bpy to the Zn surface through multi-site interactions. Additionally, the bipyridinium structure forms an electrostatic shielding layer, suppressing excessive Zn²⁺ accumulation, promoting uniform Zn deposition, and thus mitigating dendrite formation and hydrogen evolution. Consequently, the Zn||Zn symmetric cells exhibit an impressive lifespan of 250 h, while the Zn||Cu asymmetric cells achieve a high average Coulombic efficiency of 99.8% over 450 cycles. Moreover, SPr-Bpy significantly improves Zn/TEMPO flow battery performance, achieving a high areal capacity of 24.4 mAh cm^-2 with an exceptional capacity retention of 99.992%/cycle over 500 cycles.

Organic ionic plastic crystals (OIPCs) are emerging as promising electrolyte materials for solid-state batteries. However, despite the fast ionic diffusion, OIPCs exhibit relatively low DC conductivity in solid phases caused by strong ion-ion correlations that suppress charge transport. To understand the origin of this suppression, we performed a study of ion dynamics in the OIPC 1-Ethyl-1-methylpyrrolidinium bis (trifluoromethyl sulfonyl) imide [P₁₂][TFSI] utilizing dielectric spectroscopy, light scattering, and Nuclear Magnetic Resonance diffusometry. Comparison of the results obtained in this study with the published earlier results on an OIPC with a completely different structure (Diethyl(methyl)(isobutyl)phosphonium Hexafluorophosphate [P_1,2,2,4][PF₆]) revealed strong similarities in ion dynamics in both systems. Unlike DC conductivity, which may drop more than ten times between melted and solid phases, diffusion of anions and cations remains high and does not show strong changes at phase transition. The conductivity spectra in the broad frequency range demonstrate unusual shapes in solid phases with an additional step separating fast local ion motions from suppressed long-range charge diffusion controlling DC conductivity. We suggested that in solid phases, anions and cations can jump only between the specific ion sites defined by the crystalline structure. These constraints lead to strong cation-cation and anion-anion correlations strongly suppressing long-range charge transport.

The global energy crisis has driven significant research into renewable energy sources, and photoelectrochemical (PEC) water splitting stands out as one of the most promising solutions for hydrogen production. Among the various materials developed for PEC water splitting, ternary metal sulfides, particularly ZnIn₂S₄, have garnered considerable attention due to their unique combination of electronic, optical, and chemical properties. This paper presents a comprehensive analysis of the structure and properties of ZnIn₂S₄, explores modification strategies for ZnIn₂S₄-based photoanodes, and discusses their application in PEC water splitting. Furthermore, we address the challenges and limitations of ZnIn₂S₄-based photoanodes and highlight prospects for their future development.

Co-free Li-rich Mn-based cathode materials (LMNO) have gradually become powerful competitors with ultra-high specific discharge capacity and energy density. However, high-rate performance and severe voltage decay restrict the commercial application of LMNO. Herein, LiAl₅O₈ acts as a templating agent to construct 3D neural-like networks in LMNO, enabling fast ion diffusion and improving rate performance. Proton exchange is predominantly facilitated by the process of LiAl₅O₈ constructed to generate vacancies for oxygen preservation, while strong Al-O bonds stabilize interfacial lattice oxygen, effectively suppressing voltage decay due to structural evolution. As a result, the designed cathode exhibits a discharge specific capacity of 154.65 mAh g^-1 at 5 C and 91.68% capacity retention after 400 cycles (vs. 66.67% of LMNO), effectively suppressing voltage decay with 90.90% voltage retention (vs. 81.08% of LMNO). The constructed neural-like network structure engineering provides an innovative direction for improving the high-rate performance and structural stability of LMNO.

To overcome the inherent limitations in the energy generation and storage properties of transition metal-based catalysts, it is crucial to develop processes that produce catalytic materials with high performance and long-lasting effectiveness. Herein, we synthesized Metal-Organic Framework (MOF)-derived BiVO₄ by mixing two separately prepared MOFs of Bi and V using trimesic acid and terephthalic acid as linkers. The separately prepared monometallic MOFs were then mixed and carbonized in an inert atmosphere followed by oxidation in air which gives the sample BiVO₄ with carbon (BVC). The prepared BVC electrode showed the overpotential 364 mV for oxygen evolution reaction at the current density of 10 mA cm^-2. In addition, the obtained BVC supercapacitor possesses a high specific capacity of 134.17 mAh g^-1 (483 C g^-1) at 1 mA cm^-2 current density. The aqueous and solid-state symmetric supercapacitor devices were also fabricated and achieved specific capacitance of 160.9 F g^-1 and 109.8 F g^-1 at 1 mA cm^-2 current density, respectively. Moreover, the Long Short-Term Memory-based machine learning technique was employed to model, predict, and forecast the chronoamperometric stability of MOF-derived BVC electrodes for oxygen evolution reaction applications, and the capacitive retention and Coulombic efficiency BVC electrodes. The exceptional performance of the BVC electrodes is attributed to their porous structure containing conducting carbon, which offers enhanced conductivity, larger surface area and increased reactive sites for efficient electronic and ionic transfer. This novel approach to the synthesis of MOF-derived BVC has opened up new pathways for future energy storage and conversion.