The dissolution of transition metal(TM)cations from oxide cathodes and the subsequent migration and deposition on the anode lead to the deconstruction of cathode materials and uncontrollable growth of solid electrode ...The dissolution of transition metal(TM)cations from oxide cathodes and the subsequent migration and deposition on the anode lead to the deconstruction of cathode materials and uncontrollable growth of solid electrode interphase(SEI).The above issues have been considered as main causes for the performance degradation of lithium-ion batteries(LIBs).In this work,we reported that the solid oxide electrolyte Li1.5Al0.5Ti1.5(PO4)3(LATP)coating on polyethylene(PE)polymer separator can largely block the TM dissolution and deposition in LIBs.Scanning electron microscopy(SEM),second ion mass spectroscopy(SIMS),and Raman spectroscopy characterizations reveal that the granular surface of the LATP coating layer is converted to a dense morphology due to the reduction of LATP at discharge process.The as-formed dense surface layer can effectively hinder the TM deposition on the anode electrode and inhibit the TM dissolution from the cathode electrode.As a result,both the LiCoO2/SiO-graphite and LiMn2O4/SiO-graphite cells using LATP coated PE separator show substantially enhanced cycle performances compared with those cells with Al2O3 coated PE separator.展开更多
High chemical reactivity, large volume changes, and uncontrollable lithium dendrite growth have always been the key problems of lithium metal anodes.Coating has been demonstrated as an effective strategy to protect th...High chemical reactivity, large volume changes, and uncontrollable lithium dendrite growth have always been the key problems of lithium metal anodes.Coating has been demonstrated as an effective strategy to protect the lithium metal.In this work, the effects of polyacrylonitrile(PAN)-based coatings on electrodeposited lithium have been studied.Our results show that a PAN coating layer provides uniform and dendrite-free lithium deposition as well as better cycling performance with carbonate electrolyte.Notably, heat treatment of the PAN coating layer promotes the formation of larger deposit particle size and higher coulombic efficiency(85%).The compact coating layer of heat-treated PAN with a large Young modulus(82.7 GPa) may provide stable protection for the active lithium.Improved homogeneity of morphology and mechanical properties of heat-treated PAN contribute to the larger deposit particles.This work provides new feasibility to optimize the polymer coating through rational modification of polymers.展开更多
基金the National Key R&D Program of China(Grant No.2016YFB0100100)the National Natural Science Foundation of China(Grant Nos.51822211,U1932220,U1964205,and U19A2018).
文摘The dissolution of transition metal(TM)cations from oxide cathodes and the subsequent migration and deposition on the anode lead to the deconstruction of cathode materials and uncontrollable growth of solid electrode interphase(SEI).The above issues have been considered as main causes for the performance degradation of lithium-ion batteries(LIBs).In this work,we reported that the solid oxide electrolyte Li1.5Al0.5Ti1.5(PO4)3(LATP)coating on polyethylene(PE)polymer separator can largely block the TM dissolution and deposition in LIBs.Scanning electron microscopy(SEM),second ion mass spectroscopy(SIMS),and Raman spectroscopy characterizations reveal that the granular surface of the LATP coating layer is converted to a dense morphology due to the reduction of LATP at discharge process.The as-formed dense surface layer can effectively hinder the TM deposition on the anode electrode and inhibit the TM dissolution from the cathode electrode.As a result,both the LiCoO2/SiO-graphite and LiMn2O4/SiO-graphite cells using LATP coated PE separator show substantially enhanced cycle performances compared with those cells with Al2O3 coated PE separator.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51822211 and 51802342)the State Grid Technology Project,China(Grant No.DG71-17-010)
文摘High chemical reactivity, large volume changes, and uncontrollable lithium dendrite growth have always been the key problems of lithium metal anodes.Coating has been demonstrated as an effective strategy to protect the lithium metal.In this work, the effects of polyacrylonitrile(PAN)-based coatings on electrodeposited lithium have been studied.Our results show that a PAN coating layer provides uniform and dendrite-free lithium deposition as well as better cycling performance with carbonate electrolyte.Notably, heat treatment of the PAN coating layer promotes the formation of larger deposit particle size and higher coulombic efficiency(85%).The compact coating layer of heat-treated PAN with a large Young modulus(82.7 GPa) may provide stable protection for the active lithium.Improved homogeneity of morphology and mechanical properties of heat-treated PAN contribute to the larger deposit particles.This work provides new feasibility to optimize the polymer coating through rational modification of polymers.