The stable operation of solid-state lithium metal batteries at low temperatures is plagued by severe restrictions from inferior electrolyte-electrode interface compatibility and increased energy barrier for Li^(+)migr...The stable operation of solid-state lithium metal batteries at low temperatures is plagued by severe restrictions from inferior electrolyte-electrode interface compatibility and increased energy barrier for Li^(+)migration.Herein,we prepare a dual-salt poly(tetrahydrofuran)-based electrolyte consisting of lithium hexafluorophosphate and lithium difluoro(oxalato)borate(LiDFOB).The Li-salt anions(DFOB−)not only accelerate the ring-opening polymerization of tetrahydrofuran,but also promote the formation of highly ion-conductive and sustainable interphases on Li metal anodes without sacrificing the Li^(+)conductivity of electrolytes,which is favorable for Li^(+)transport kinetics at low temperatures.Applications of this polymer electrolyte in Li||LiFePO_(4)cells show 82.3%capacity retention over 1000 cycles at 30℃and endow stable discharge capacity at−30℃.Remarkably,the Li||LiFePO4 cells retain 52%of their room-temperature capacity at−20℃and 0.1 C.This rational design of dual-salt polymer-based electrolytes may provide a new perspective for the stable operation of quasi-solid-state batteries at low temperatures.展开更多
The sluggish ion transport and deteriorating electrode-electrolyte interphase hinder the performance of lithium-ion batteries under wide temperature operation,thereby posing substantial challenges in improving both hi...The sluggish ion transport and deteriorating electrode-electrolyte interphase hinder the performance of lithium-ion batteries under wide temperature operation,thereby posing substantial challenges in improving both high-voltage and high-rate performance.Herein,the competitive ion-molecule-coordinated interactions(Li+-anion-solvent-diluent)achieve a balance that directs an anion-dominated and moderate diluent-interacting solvation structure,resulting in an excellent wide-temperature electrolyte with electrochemical stability up to 5.4 V and high Li-ion conductivity(1.034 mS/cm at-60℃).The corresponding NCM811||Li cells exhibit capacity retention ratios of 90.74%after 200 cycles at-40℃ and 54.68%for 250 cycles at 70℃.Additionally,the cell achieves stable cycling performance at a high rate of 10 C at 25℃.Notably,the assembled NCM811||Graphite pouch battery(3 Ah)can be operated at-106℃ and possesses 2.6 Ah at-30℃,with 90.28%capacity retention after 90 cycles and stable cycling performance at 50℃.This work provides a new design principle for electrolyte,which may expedite the development of ultra-wide-temperature lithium-ion batteries.展开更多
基金funding from the Natural Science Foundation of Hubei Province,China(Grant No.2022CFA031)supported by the Natural Science Foundation of China(Grant No.22309056).
文摘The stable operation of solid-state lithium metal batteries at low temperatures is plagued by severe restrictions from inferior electrolyte-electrode interface compatibility and increased energy barrier for Li^(+)migration.Herein,we prepare a dual-salt poly(tetrahydrofuran)-based electrolyte consisting of lithium hexafluorophosphate and lithium difluoro(oxalato)borate(LiDFOB).The Li-salt anions(DFOB−)not only accelerate the ring-opening polymerization of tetrahydrofuran,but also promote the formation of highly ion-conductive and sustainable interphases on Li metal anodes without sacrificing the Li^(+)conductivity of electrolytes,which is favorable for Li^(+)transport kinetics at low temperatures.Applications of this polymer electrolyte in Li||LiFePO_(4)cells show 82.3%capacity retention over 1000 cycles at 30℃and endow stable discharge capacity at−30℃.Remarkably,the Li||LiFePO4 cells retain 52%of their room-temperature capacity at−20℃and 0.1 C.This rational design of dual-salt polymer-based electrolytes may provide a new perspective for the stable operation of quasi-solid-state batteries at low temperatures.
基金supported by the National Natural Science Foundation of China(52377220)the Natural Science Foundation of Changsha,Hunan Province,China(kq2208265)the State Key Laboratory of Powder Metallurgy at Central South University,and the High Performance Computing Center of Central South University。
文摘The sluggish ion transport and deteriorating electrode-electrolyte interphase hinder the performance of lithium-ion batteries under wide temperature operation,thereby posing substantial challenges in improving both high-voltage and high-rate performance.Herein,the competitive ion-molecule-coordinated interactions(Li+-anion-solvent-diluent)achieve a balance that directs an anion-dominated and moderate diluent-interacting solvation structure,resulting in an excellent wide-temperature electrolyte with electrochemical stability up to 5.4 V and high Li-ion conductivity(1.034 mS/cm at-60℃).The corresponding NCM811||Li cells exhibit capacity retention ratios of 90.74%after 200 cycles at-40℃ and 54.68%for 250 cycles at 70℃.Additionally,the cell achieves stable cycling performance at a high rate of 10 C at 25℃.Notably,the assembled NCM811||Graphite pouch battery(3 Ah)can be operated at-106℃ and possesses 2.6 Ah at-30℃,with 90.28%capacity retention after 90 cycles and stable cycling performance at 50℃.This work provides a new design principle for electrolyte,which may expedite the development of ultra-wide-temperature lithium-ion batteries.
