Polymeric materials have many applications in multiple industries. In this paper, silicon nitride nanoparticles (Si₃N₄) were incorporated into a polyimide (PI) matrix to obtain composite films via the in situ polymerization method. The Si₃N₄ nanoparticles were consistently scattered in the composites, and the thickness of PI/Si₃N₄ films was around 50 µm. The effects of nanoparticle content on the dielectric constant, loss tangent and breakdown strength were simultaneously studied. A 3 wt.% doped PI/Si₃N₄ film revealled excellent dielectric properties, a dielectric constant (ε) of 3.62, a dielectric loss tangent (tanδ) of 0.038, and a breakdown strength of 237.42 MV/m. The addition of Si₃N₄ formed an interface layer inside PI, resulting in a large amount of space charge polarization in the electric field. The space charge of materials from the microscopic point of view was analyzed. The results show that there are trapenergy levels in the composites, which can be used as a composite carrier center and transport channel, effectively improving the performance of a small amount of nanoparticles film.

Aqueous zinc-ion batteries (AZIBs) have become a promising and cost-effective alternative to lithium-ion batteries due to their low cost, high energy, and high safety. However, dendrite growth, hydrogen evolution reactions (HERs), and corrosion significantly restrict the performance and scalability of AZIBs. We propose the introduction of a BaTiO₃ (BTO) piezoelectric polarized coating as an interface modification strategy for ZIBs. The low surface energy of the BTO (110) crystal plane ensures its thermodynamic preference during crystal growth in experimental processes and exhibits very low reactivity toward oxidation and corrosion. Calculations of interlayer coupling mechanisms reveal a stable junction between BTO (110) and Zn (002), ensuring system stability. Furthermore, the BTO (110) coating also effectively inhibits HERs. Diffusion kinetics studies of Zn ions demonstrate that BTO effectively suppresses the dendrite growth of Zn due to its piezoelectric effect, ensuring uniform zinc deposition. Our work proposes the introduction of a piezoelectric material coating into AZIBs for interface modification, which provides an important theoretical perspective for the mechanism of inhibiting dendrite growth and side reactions in AZIBs.

A dual-salt carbonate electrolyte is designed for low temperature lithium metal batteries. LiDFOB is preferential reduced to construct a LiF-rich SEI. Concurrently, EMC weaken the Li ⁺ solvation structure, facilitating favorable desolvation kinetics.

Fast charging of lithium-ion batteries (LIBs) is essential for emerging applications such as electric aircraft and aerial logistics. However, graphite anodes, which dominate commercial LIBs, are intrinsically constrained by orientation-dependent interparticle lithiation, leading to pronounced diffusion barriers, reaction heterogeneity, and lithium plating under high-rate. Herein, a graphite/hard carbon composite anode is developed via a scalable ball-milling strategy to overcome sluggish interparticle lithiation kinetics. The composite anode delivers 48% of its 0.2 C capacity at 5 C and retains 83.3% over 3000 cycles at 10 C; the LiFePO4 pouch cell further sustains 6 C operation for 800 cycles, evidencing exceptional fast-charging durability. In-situ Raman, multiphysics simulations, and state-of-charge-resolved diffusion analysis reveal that the performance enhancement originates from asynchronous lithiation between graphite and hard carbon arising from their distinct equilibrium potentials and kinetic characteristics. This non-equilibrium lithiation sustains interfacial Li+ diffusion, alleviates localized overpotential buildup, and mitigates reaction heterogeneity, resulting in a more uniform, inorganic-rich solid electrolyte interphase with lower Li+ transport resistance and suppressed dendrite growth. This work highlights interparticle ion redistribution as a critical yet overlooked factor governing fast-charging behavior and provides mechanistic guidance for designing composite graphite anodes for practical fast charging LIBs.

Aqueous energy storage is attractive for safe and sustainable applications; however, its energy density remains intrinsically limited by the trade-off between ionic conductivity and electrochemical stability window arising from water-dominated solvation, which becomes particularly severe at low temperatures. Herein, a dual-salt-based strategy to regulate solvation chemistry toward a water-depleted state without sacrificing low-temperature ionic conductivity and electrochemical stability is developed. By incorporating LiCl/LiNO3 dual salts into a Mg(ClO4)2-urea matrix, water molecules in the primary solvation shell are replaced by small-sized urea molecules together with coordinating anions, effectively suppressing interfacial water splitting while preserving high ionic conductivity. As a result, the optimized electrolyte exhibits a wide electrochemical stability window of 3.9 V at 25 oC and retains a high ionic conductivity of 4.2 mS cm-1 at -40 oC. When applied in a VO2//activated carbon hybrid supercapacitor, it delivers a specific capacitance of 41 F g-1 at -40 oC and maintains 86% capacitance retention after 10000 cycles at -30 oC. Molecular dynamics simulations reveal that a concentration-dependent transition from water-rich to water-depleted solvation governs the trade-off between ion mobility and electrochemical stability. This study offers mechanistic insights into electrolyte design principles for aqueous energy storage under low-temperature, high-rate operating conditions.