As the persistent concerns regarding sluggish reaction kinetics and insufficient conductivities of sulfur cathodes in all-solid-state Li–S batteries (ASSLSBs), numerous carbon additives and solid-state electrolytes (SSEs) have been incorporated into the cathode to facilitate ion/electron pathways around sulfur. However, this has resulted in a reduced capacity and decomposition of SSEs. Therefore, it is worth exploring neotype sulfur hosts with electronic/ionic conductivity in the cathode. Herein, we present a hybrid cathode composed of few-layered S/MoS₂/C nanosheets (<5 layers) that exhibits high-loading and long-life performance without the need of additional carbon additives in advanced ASSLSBs. The multifunctional MoS₂/C host exposes the abundant surface for intimate contacting sites, in situ-formed Li_xMoS₂ during discharging as mixed ion/electron conductive network improves the S/Li₂S conversion, and contributes extra capacity for the part of active materials. With a high active material content (S + MoS₂/C) of 60 wt% in the S/MoS₂/C/Li₆PS₅Cl cathode composite (the carbon content is only ~3.97 wt%), the S/MoS₂/C electrode delivers excellent electrochemical performance, with a high reversible discharge capacity of 980.3 mAh g⁻¹ (588.2 mAh g⁻¹ based on the whole cathode weight) after 100 cycles at 100 mA g⁻¹. The stable cycling performance is observed over 3500 cycles with a Coulombic efficiency of 98.5% at 600 mA g⁻¹, while a high areal capacity of 10.4 mAh cm⁻² is achieved with active material loading of 12.8 mg cm⁻².

Composite polymer electrolytes (CPEs) have attracted much attention for high energy density solid-state lithium-metal batteries owing to their flexibility, low cost, and easy scale-up. However, the unstable Li/CPE interface is always challengeable for the practical utilization of CPEs. Herein, a polymer interlayer containing K⁺ prepared by ultraviolet (UV)-curing precursor solution is coated on Li surface to stabilize the interface between poly(vinylidene difluoride) (PVDF) composite electrolytes and Li anode. Benefiting from the physical barrier of the interlayer, the continuous decomposition of PVDF is restrained and the intimate contact between electrode and electrolyte is also achieved to reduce the interface impedance. Moreover, the added K⁺ is utilized to further regulate smooth Li deposition. As a consequence, the symmetric Li|Li cell with coated Li demonstrates steady cycling at 0.4 mAh·cm⁻² and a high critical current density of 1 mA·cm⁻². The assembled Li|LiFePO₄ cell presents outstanding cycling stability (capacity retention of 90% after 400 cycles at 1 C) and good rate performance. The associated pouch cell performs impressive flexibility and safety. This work provides a convenient strategy to achieve stable Li/PVDF interface for high-performance PVDF-based solid state Li metal batteries.

The point-to-point contact mechanism in all-solid-state Li-S batteries (ASSLSBs) is not as efficient as a liquid electrolyte which has superior mobility in the electrode, resulting in a slower reaction kinetics and inadequate ionic/electronic conduction network between the S (or Li₂S), conductive carbon, and solid-state electrolytes (SSEs) for achieving a swift (dis)charge reaction. Herein, a series of hybrid ionic/electronic conduction triple-phase interfaces with transition metal and nitrogen co-doping were designed. The graphitic ordered mesoporous carbon frameworks (TM-N-OMCs; TM = Fe, Co, Ni, and Cu) serve as hosts for Li₂S and Li₆PS₅Cl (LPSC) and provide abundant reaction sites on the triple interface. Results from both experimental and computational research display that the combination of Cu-N co-dopants can promote the Li-ion diffusion for rapid transformation of Li₂S with adequate ionic (6.73 × 10⁻⁴ S·cm⁻¹)/electronic conductivities (1.77 × 10⁻² S·cm⁻¹) at 25 °C. The as-acquired Li₂S/Cu-N-OMC/LPSC electrode exhibits a high reversible capacity (1147.7 mAh·g⁻¹) at 0.1 C, excellent capacity retention (99.5%) after 500 cycles at 0.5 C, and high areal capacity (7.08 mAh·cm⁻²).

Cluster catalysts are rapidly growing into an important sub-field in heterogeneous catalysis, owing to their distinct geometric structure, neighboring metal sites, and unique electronic structure. Although the thermodynamics and kinetics of the formation of nanoparticles have been largely investigated, the precise synthesis of clusters in wet chemical methods still faces great challenges. In the study, a quenching strategy of asymmetric temperature in solution for the rapid generation of vacancy-defect rich clusters is reported. The quenching process can be used to synthesize multitudinous metal compound clusters, including metal oxides, fluorides, oxygen-sulfur compounds, and tungstate. For oxygen evolution reaction (OER), IrO₂ clusters with abundant oxygen vacancies were obtained and uniformly dispersed in the solution. Compared to commercial IrO₂, the prepared IrO₂ cluster can be directly loaded on carbon paper and used as binder-free electrodes, which exhibit higher OER activity and long-term operational stability in alkaline electrolytes. The quenching strategy provides a simple and efficient method for the synthesis of clusters, which has tremendous potential for industrial-scale preparation and application, especially can be further applied to flow electrochemical generators.

The rational design and construction of hierarchically porous nanostructure for oxygen reduction reaction (ORR) electrocatalysts is crucial to facilitate the exposure of accessible active sites and promote the mass/electron transfer under the gas-solid-liquid triple-phase condition. Herein, an ingenious method through the pyrolysis of creative polyvinylimidazole coordination with Zn/Fe salt precursors is developed to fabricate hierarchically porous Fe-N-doped carbon framework as efficient ORR electrocatalyst. The volatilization of Zn species combined with the nanoscale Kirkendall effect of Fe dopants during the pyrolysis build the hierarchical micro-, meso-, and macroporous nanostructure with a high specific surface area (1, 586 m²·g⁻¹), which provide sufficient exposed active sites and multiscale mass/charge transport channels. The optimized electrocatalyst exhibits superior ORR activity and robust stability in both alkaline and acidic electrolytes. The Zn-air battery fabricated by such attractive electrocatalyst as air cathode displays a higher peak power density than that of Pt/C-based Zn-air battery, suggesting the great potential of this electrocatalyst for Zn-air batteries.