Jiao-Jing Shao

Lithium–sulfur (Li–S) batteries are regarded as a promising candidate for next-generation high-energy-density storage systems due to their high theoretical energy density and the abundant availability of sulfur resources. However, practical applications are severely constrained by the shuttle effect of soluble lithium polysulfides (LiPSs) and the sluggish kinetics of Li2S deposition/decomposition. To address the challenge of simultaneously optimizing adsorption capacity and catalytic activity toward sulfur species conversion, this work proposes an interfacial electronic structure regulation strategy and constructs a composite host comprising VC/WC heterogeneous carbides and nitrogen-doped carbon nanotubes (W-VC@NCNTs). Through hydrothermal assembly and high-temperature carbonization, VC and WC nanocrystallites were in situ fabricated on the surface of nitrogen-doped carbon nanotubes. Benefiting from the moderate downshift of the d-band center induced by electron transfer from V to W at the VC/WC heterointerface, the composite achieves effective chemical anchoring of LiPSs while avoiding product poisoning caused by excessively strong adsorption, thereby realizing an optimal balance between adsorption strength and catalytic activity. Combined with the continuous electron/ion transport pathways provided by the defect-rich nitrogen-doped carbon network, the bidirectional energy barriers for Li2S nucleation and oxidative decomposition are significantly reduced. Experimental results demonstrate that the W-VC@NCNTs electrode exhibits faster charge transfer, lower interfacial polarization, and superior Li2S nucleation/decomposition kinetics, with a capacity decay rate of only 0.062% per cycle over 500 cycles at 1 C. This study elucidates the mechanism by which interfacial electronic modulation in heterogeneous carbides promotes polysulfide catalytic conversion, offering an effective strategy for the design of sulfur host materials for high-performance Li–S batteries.

Lithium metal batteries (LMBs) have undergone extensive development owing to their remarkable energy storage capabilities. Nevertheless, safety concerns, including thermal runaway and lithium dendrites, impede their application. Modification of separators can effectively overcome the limitations of commercial separators, such as inferior thermal stability and poor wettability, and consequently alleviate the damage induced by lithium dendrites. Here, we synthesize a three-dimensional P-type molecular sieve and develop a lamellar-structured material, which is then used to fabricate composite separators by coating it onto polypropylene (PP) separators (denoted as PP@3DP and PP@TOC/3DP). Experimental results demonstrate that, in comparison with pristine PP separators, the composite separators display significantly enhanced physical properties, such as improved porosity, thermal stability, and tensile strength. The battery assembled with the PP@TOC/3DP separator exhibits a higher initial discharge specific capacity (167.96 mAh g^-1), superior rate performance, and enhanced cycling stability at 0.5 C, compared to batteries assembled with the PP separator and the PP@3DP separator. Moreover, after 1000 cycles at 2.0 C, it sustains a capacity retention rate of 95.90% with a specific capacity of 140.36 mAh g^-1. These findings strongly attest to the excellent performance of PP@TOC/3DP and pave the way for molecular sieve functionalized separators in LMBs.

The polyethylene oxide/polyvinylidene fluoride-hexafluoropropylene (PEO/PVDF-HFP) blended gel polymer electrolyte (GPE) combines high ionic conductivity of PEO with the excellent mechanical robustness and wide electrochemical stability window of PVDF-HFP, rendering it a highly electrolyte platform for lithium metal batteries (LMBs). However, intrinsic incompatibility-induced severe phase separation disrupts continuous Li ⁺ transport pathways and degrades electrochemical performance. Herein, rod-like MgAlF ₅ ·1.5H ₂ O (MAF) nanocrystals with tunable fluorine vacancies are introduced as multifunctional inorganic compatibilizers to address this challenge. Owing to surface fluorine vacancies and hydroxyl groups, MAF nanocrystals can simultaneously bond with both PEO and PVDF-HFP polymer chains, acting as “molecular bridges” to construct a uniform interpenetrating polymer network. This effectively suppresses phase separation, reduces polymer crystallinity, and promotes rapid lithium-ion transport. The optimized GPE exhibits a high ionic conductivity of 2.82 mS cm ^-1 and a Li ⁺ transference number of 0.68 at room temperature. LiFePO ₄ ‖Li and LiCoO ₂ ‖Li cells demonstrate high initial specific capacities (160 and 171 mAh g ^-1 ) and good capacity retention at 1 C, while stable lithium plating/stripping is maintained for over 1300 h at 1 mA cm ^–2 . This work presents a novel strategy for regulating the phase behavior of blended polymer electrolytes and provides new insights for the development of high-performance LMBs.

Lithium‐sulfur batteries are one of the most promising next‐generation energy storage systems, while their real application is largely limited by the shuttle effect of lithium polysulfides (LiPSs). Herein, an interlayer based on a heterostructure consisting of MXene and two‐dimensional montmorillonite (MXene@MMT) is developed via an electrostatic self‐assembly strategy. Such a heterostructure possesses strong adsorption ability for LiPSs and can accelerate the conversion reaction from liquid LiPSs to solid Li ₂ S in virtue of its strong adsorption, high conductivity, and good catalytic activity. Furthermore, this heterostructure not only effectively blocks the migration of polysulfides, but also provides low energy barrier and rich pathways for Li ⁺ transport. Ultimately, the as‐assembled Li–S batteries with the MXene@MMT based interlayer deliver a high initial discharge capacity of 1375.5 mAh g ⁻¹ at 0.1C and long‐term cycling stability with 500 mAh g ⁻¹ remaining over 500 cycles under a high rate of 2C. In a practical demonstration, the as‐sembled soft pack battery achieved an initial discharge capacity of 733 mAh g ⁻¹ at 0.1C and still retained a high capacity of 402 mAh g ⁻¹ after 100 cycles.

Aqueous zinc-ion batteries (ZIBs) have attracted growing interest as promising candidates for large-scale and flexible energy storage due to their intrinsic safety, low cost, and environmental sustainability. However, several persistent issues—such as uncontrolled Zn dendrite growth, hydrogen evolution-induced anode corrosion, and cathode dissolution—continue to hinder their commercial deployment. To address these challenges, hydrogel polymer electrolytes (HPEs) have emerged as an effective strategy. Their unique three-dimensional polymer networks not only retain water and confine ion transport, but also provide a solid–liquid hybrid environment that enhances ionic conductivity and interfacial compatibility. These features enable HPEs to suppress side reactions and improve both electrochemical stability and mechanical adaptability, which are especially valuable for flexible ZIB devices. This review first summarizes fundamental energy storage mechanisms in aqueous ZIBs, including reversible Zn²⁺ insertion/extraction, proton co-insertion, and cathode phase evolution. It then highlights recent progress in HPE design, with emphasis on polyacrylamide (PAM), polyvinyl alcohol (PVA), and polyacrylic acid (PAA)-based systems, with strategies for dendrite suppression, interfacial regulation, and mechanical robustness. Finally, current challenges and future directions are discussed, with a forward-looking perspective on scalable fabrication methods, advanced electrolyte design, and deeper mechanistic understanding necessary to fully realize the potential of HPE-enabled aqueous ZIBs.

Lithium-sulfur (Li-S) batteries are considered a promising next-generation energy storage system owing to their exceptionally high theoretical energy density. However, their practical deployment is hindered by the severe polysulfide shuttle effect arising from the dissolution and migration of lithium polysulfides. Herein, we report the rational design of a hierarchical freestanding cathode architecture consisting of carbon nanotube-embedded porous carbon nanofibers (PCNF/T) decorated with in situ grown CoS₂ nanocrystals (PCNF/T@CoS₂). This integrated structure is fabricated via electrospinning, high-temperature carbonization, and a subsequent hydrothermal process. Uniquely, the flexible, binder-free cathode directly replaces traditional aluminum foil current collectors. The 3D conductive framework not only accommodates volume fluctuations during cycling but also enables efficient charge transport. Meanwhile, CoS₂ nanocrystals synergistically suppress polysulfide migration via a combination of strong chemical anchoring and physical confinement, as confirmed by density functional theory (DFT) calculations. Benefiting from this multiscale structural and chemical synergy, the optimized cathode exhibits a high initial capacity of 955.5 mAh g^-1 at 1 C with an ultralow capacity fading rate of 0.07% per cycle over 310 cycles. Even at a high sulfur loading of 6.7 mg cm^-2, the battery can still retain a capacity of 521 mAh g^-1 after 100 cycles. This work offers a viable strategy toward the development of high-loading, long-life Li-S battery cathodes.

Developing low-cost and high-efficiency OER electrocatalysts holds the key to hydrogen production from electrochemical water splitting. In this study, cobalt sulfide hollow nanospheres derived from ZIF-67 were immobilized on a potato starch-derived carbon aerogel (Co-S@CA) using a solvothermal method followed by annealing. The synergistic effects of Co-S and three-dimensional carbon aerogel (CA) facilitate rapid charge transfer, high electrochemical surface area, and better electronic structure, enhancing the electrochemical activity of the composite. The synthesized Co-S@CA catalyst exhibited remarkable catalytic performance with an overpotential of 291 mV at 10 mA cm^-2 and a Tafel slope of 61.8 mV dec^-1, outperforming the commercial RuO₂ catalyst. The Co-S@CA catalyst demonstrates excellent stability with negligible increase in overpotential after 60 h of a stability test. Density functional theory (DFT) calculations further supported the experimental results, showing that the interfacial charge transfer between Co-S and carbon generates a built-in electric field and upshifts the d-band center, enhancing charge-transfer capability and lowering the theoretical overpotential for the OER. These improvements significantly boost the catalytic activity. This study highlights the potential of Co-S@CA composites as highly efficient electrocatalysts for renewable energy applications.