Lithium(Li)penetration through solid electrolytes(SEs)induces short circuits in Li solid-state batteries(SSBs),which is a critical issue that hinders the development of high energy density SSBs.While cracking in ceram...Lithium(Li)penetration through solid electrolytes(SEs)induces short circuits in Li solid-state batteries(SSBs),which is a critical issue that hinders the development of high energy density SSBs.While cracking in ceramic SEs has been often shown to accompany Li penetration,the interplay between Li deposition and cracking remains elusive.Here,we constructed a mesoscale SSB inside a focused ion beam-scanning electron microscope(FIB-SEM)for in situ observation of Li deposition-induced cracking in SEs at nanometer resolution.Our results revealed that Li propagated predominantly along transgranular cracks in a garnet Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO).Cracks appeared to initiate from the interior of LLZTO beneath the electrode surface and then propagated by curving toward the LLZTO surface.The resulting bowl-shaped cracks resemble those from hydraulic fracture caused by high fluid pressure on the surface of internal cracks,suggesting that the Li deposition-induced pressure is the major driving force of crack initiation and propagation.The high pressure generated by Li deposition is further supported by in situ observation of the flow of filled Li between the crack flanks,causing crack widening and propagation.This work unveils the dynamic interplay between Li deposition and cracking in SEs and provides insight into the mitigation of Li dendrite penetration in SSBs.展开更多
The corrosion behavior of pure Mg,AZ31,and AZ91D were evaluated in various in vitro and in vivo environments to investigate the potential application of these metals as biodegradable implant materials.DC polarization ...The corrosion behavior of pure Mg,AZ31,and AZ91D were evaluated in various in vitro and in vivo environments to investigate the potential application of these metals as biodegradable implant materials.DC polarization tests and immersion tests were performed in different simulated body solutions,such as distilled(DI) water,simulated body fluid(SBF) and phosphate buffered solution(PBS).Mg/Mg alloys were also implanted in different places in a mouse for in vivo weight loss and biocompatibility investigations.The in vivo subcutis bio-corrosion rate was lower than the corrosion rate for all of the in vitro simulated corrosive environments.The Mg/Mg alloys were biocompatible based on histology results for the liver,heart,kidney,skin and lung of the mouse during the two months implantation.Optical microscopy and scanning electron microscopy were carried out to investigate the morphology and topography of Mg/Mg alloys after immersion testing and implantation to understand the corrosion mechanisms.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52022088,51971245,51772262,21406191,U20A20336,21935009,51771222,52002197)Beijing Natural Science Foundation(2202046)+3 种基金Fok Ying-Tong Education Foundation of China(No.171064)Natural Science Foundation of Hebei Province(No.F2021203097,B2020203037,B2018203297)Hunan Innovation Team(2018RS3091)supported by the Assistant Secretary for Energy,Vehicles Technology Office,of the U.S.Department of Energy under Contract(No.DEAC02-05CH11231).
文摘Lithium(Li)penetration through solid electrolytes(SEs)induces short circuits in Li solid-state batteries(SSBs),which is a critical issue that hinders the development of high energy density SSBs.While cracking in ceramic SEs has been often shown to accompany Li penetration,the interplay between Li deposition and cracking remains elusive.Here,we constructed a mesoscale SSB inside a focused ion beam-scanning electron microscope(FIB-SEM)for in situ observation of Li deposition-induced cracking in SEs at nanometer resolution.Our results revealed that Li propagated predominantly along transgranular cracks in a garnet Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO).Cracks appeared to initiate from the interior of LLZTO beneath the electrode surface and then propagated by curving toward the LLZTO surface.The resulting bowl-shaped cracks resemble those from hydraulic fracture caused by high fluid pressure on the surface of internal cracks,suggesting that the Li deposition-induced pressure is the major driving force of crack initiation and propagation.The high pressure generated by Li deposition is further supported by in situ observation of the flow of filled Li between the crack flanks,causing crack widening and propagation.This work unveils the dynamic interplay between Li deposition and cracking in SEs and provides insight into the mitigation of Li dendrite penetration in SSBs.
基金sponsored by the National Science Foundation(NSF) Engineering Research Center(ERC) for Revolutionizing Metallic Biomaterials(RMB)the Business for International Cooperative Research and Development between Industry,Academy and Research Institute funded by the Korean Small and Medium Business Administration(No.00042172-1)
文摘The corrosion behavior of pure Mg,AZ31,and AZ91D were evaluated in various in vitro and in vivo environments to investigate the potential application of these metals as biodegradable implant materials.DC polarization tests and immersion tests were performed in different simulated body solutions,such as distilled(DI) water,simulated body fluid(SBF) and phosphate buffered solution(PBS).Mg/Mg alloys were also implanted in different places in a mouse for in vivo weight loss and biocompatibility investigations.The in vivo subcutis bio-corrosion rate was lower than the corrosion rate for all of the in vitro simulated corrosive environments.The Mg/Mg alloys were biocompatible based on histology results for the liver,heart,kidney,skin and lung of the mouse during the two months implantation.Optical microscopy and scanning electron microscopy were carried out to investigate the morphology and topography of Mg/Mg alloys after immersion testing and implantation to understand the corrosion mechanisms.