Composite solid-state electrolytes(CSEs)are promising candidates for solid-state sodium batteries.However,achieving high ionic conductivity while maintaining adequate mechanical strength presents a significant challen...Composite solid-state electrolytes(CSEs)are promising candidates for solid-state sodium batteries.However,achieving high ionic conductivity while maintaining adequate mechanical strength presents a significant challenge.For roll-to-roll manufacturing,researchers have sought to incorporate an inert framework,such as polyethylene(PE)separators,as substrates for ultra-thin CSEs membranes.Nevertheless,these inert substrates result in poor ionic conductivity and uneven sodium ion(Na^(+))flux,promoting sodium dendrite growth.Here,we propose a flexible and ion-conducting framework based on polymer-reinforced-ceramic(PRC)electrospun fibers.This design features a poly(vinylidene fluoride)(PVDF)-based polymer electrolyte as a flexible core and an Na_(3)Zr_(2)Si_(2)PO_(12)(NZSP)-based ceramic electrolyte as a rigid shell.A continuous Na^(+)conduction pathway is created in the PRC fiber by taking advantage of the superior Na^(+)-conduction behavior along the interface between NZSP nanoparticles and PVDF polymer.A tape-casted ultra-thin composite electrolyte membrane(thickness:17.8μm)based on the PRC three-dimensional(3D)framework exhibits sufficient ionic conductivity(6.6×10^(-4)S cm^(-1),60℃)and enables a stable Na plating/stripping in symmetric Na/Na cells and a long-term cycling of solidstate Na-metal batteries.The suppressed sodium dendrite can be attributed to the Na_(3)P-rich SEIs derived from the NZSP shells in the PRC frameworks.This work provides a novel strategy for designing ionconducting frameworks for ultra-thin CSEs membranes and promotes potential applications in highperformance solid-state sodium metal batteries.展开更多
Despite being pursued for a long time, hydrogen production via water splitting is still a huge challenge mainly due to a lack of durable and efficient catalysts. Molybdenum phosphide （MOP） is theoretically capable o...Despite being pursued for a long time, hydrogen production via water splitting is still a huge challenge mainly due to a lack of durable and efficient catalysts. Molybdenum phosphide （MOP） is theoretically capable of efficient hydrogen evolution reaction （HER） catalysis, however, there is still room for further improvement in its performance. Herein, we propose a design for MoP with a P-rich outermost atomic layer for enhancing HER via complementary theoretical and experimental validation. The correlation of computational results suggests that the P-terminated surface of MoP plays a crucial role in determining its high-efficiency catalytic properties. We fabricated a P-rich outermost atomic layer of MoP nanoparticles by using N-doped porous carbon （MoP@NPCNFs） to capture more P on the surface of MoP and limit the growth of nanoparticles. Further, the as-prepared material can be directly employed as a self-supported electrocatalyst, and it exhibits remarkable electrocatalytic activity for HER in acidic media; it also reveals excellent long-term durability for up to 5,000 cycles with negligible loss of catalytic activity.展开更多
基金supported by the National Key R&D Program of China(2023YFB2503900)the National Natural Science Foundation of China(12474171 and 52372203)。
文摘Composite solid-state electrolytes(CSEs)are promising candidates for solid-state sodium batteries.However,achieving high ionic conductivity while maintaining adequate mechanical strength presents a significant challenge.For roll-to-roll manufacturing,researchers have sought to incorporate an inert framework,such as polyethylene(PE)separators,as substrates for ultra-thin CSEs membranes.Nevertheless,these inert substrates result in poor ionic conductivity and uneven sodium ion(Na^(+))flux,promoting sodium dendrite growth.Here,we propose a flexible and ion-conducting framework based on polymer-reinforced-ceramic(PRC)electrospun fibers.This design features a poly(vinylidene fluoride)(PVDF)-based polymer electrolyte as a flexible core and an Na_(3)Zr_(2)Si_(2)PO_(12)(NZSP)-based ceramic electrolyte as a rigid shell.A continuous Na^(+)conduction pathway is created in the PRC fiber by taking advantage of the superior Na^(+)-conduction behavior along the interface between NZSP nanoparticles and PVDF polymer.A tape-casted ultra-thin composite electrolyte membrane(thickness:17.8μm)based on the PRC three-dimensional(3D)framework exhibits sufficient ionic conductivity(6.6×10^(-4)S cm^(-1),60℃)and enables a stable Na plating/stripping in symmetric Na/Na cells and a long-term cycling of solidstate Na-metal batteries.The suppressed sodium dendrite can be attributed to the Na_(3)P-rich SEIs derived from the NZSP shells in the PRC frameworks.This work provides a novel strategy for designing ionconducting frameworks for ultra-thin CSEs membranes and promotes potential applications in highperformance solid-state sodium metal batteries.
文摘Despite being pursued for a long time, hydrogen production via water splitting is still a huge challenge mainly due to a lack of durable and efficient catalysts. Molybdenum phosphide （MOP） is theoretically capable of efficient hydrogen evolution reaction （HER） catalysis, however, there is still room for further improvement in its performance. Herein, we propose a design for MoP with a P-rich outermost atomic layer for enhancing HER via complementary theoretical and experimental validation. The correlation of computational results suggests that the P-terminated surface of MoP plays a crucial role in determining its high-efficiency catalytic properties. We fabricated a P-rich outermost atomic layer of MoP nanoparticles by using N-doped porous carbon （MoP@NPCNFs） to capture more P on the surface of MoP and limit the growth of nanoparticles. Further, the as-prepared material can be directly employed as a self-supported electrocatalyst, and it exhibits remarkable electrocatalytic activity for HER in acidic media; it also reveals excellent long-term durability for up to 5,000 cycles with negligible loss of catalytic activity.
