The solid-state polymer electrolyte fabricated by ring-opening polymerization(ROP)of cyclic ether has been known as an efficient means to increase high-voltage stability despite the challenges of uncontrolled degrees ...The solid-state polymer electrolyte fabricated by ring-opening polymerization(ROP)of cyclic ether has been known as an efficient means to increase high-voltage stability despite the challenges of uncontrolled degrees of polymerization and low ionic conductivity.Here,through unveiling the ROP mechanism of a conventional cyclic ether(1,3-dioxolane),we found that through molecular engineering of the methoxyl(–OCH_(3))on the skeleton of the ring,the ROP is not thermodynamically favorable due to its dispersed electron density.Simultaneously,the electron-withdrawing characteristics of–OCH_(3) increase the high-voltage stability,enabling compatibility with the high-voltage cathode without the need for polymerization.Moreover,using lithium bis(fluorosulfonyl)imide(LiFSI)as a single salt,the merits of weak solvation capability promote the formation of inorganic rich solid electrolyte interphase and provide the coulombic efficiency of 99.36%for lithium striping/plating.The lithium metal batteries using a LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2) cathode and thin lithium(50μm)can maintain ultralong cycling performance up to 1180 cycles(80%capacity retention)or calendar life over 6500 h(more than nine months).Our work deepens the fundamental understanding of how ROP regulates electrochemical reactions and affords an effective approach to designing cyclic ether electrolytes for energy-dense battery systems.展开更多
基金supported by the National Natural Science Foundation of China(grant nos.22372083,52201259,and 22393900)the Young Elite Scientist Sponsorship Program by China Association for Science and Technology,the National Key R&D Program of China(grant no.2021YFB2500300)the Natural Science Foundation of Tianjin(grant no.22JCZDJC00380).
文摘The solid-state polymer electrolyte fabricated by ring-opening polymerization(ROP)of cyclic ether has been known as an efficient means to increase high-voltage stability despite the challenges of uncontrolled degrees of polymerization and low ionic conductivity.Here,through unveiling the ROP mechanism of a conventional cyclic ether(1,3-dioxolane),we found that through molecular engineering of the methoxyl(–OCH_(3))on the skeleton of the ring,the ROP is not thermodynamically favorable due to its dispersed electron density.Simultaneously,the electron-withdrawing characteristics of–OCH_(3) increase the high-voltage stability,enabling compatibility with the high-voltage cathode without the need for polymerization.Moreover,using lithium bis(fluorosulfonyl)imide(LiFSI)as a single salt,the merits of weak solvation capability promote the formation of inorganic rich solid electrolyte interphase and provide the coulombic efficiency of 99.36%for lithium striping/plating.The lithium metal batteries using a LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2) cathode and thin lithium(50μm)can maintain ultralong cycling performance up to 1180 cycles(80%capacity retention)or calendar life over 6500 h(more than nine months).Our work deepens the fundamental understanding of how ROP regulates electrochemical reactions and affords an effective approach to designing cyclic ether electrolytes for energy-dense battery systems.
