Ion migration capability and interfacial chemistry of solid polymer electrolytes(SPEs)in all-solid-state sodium metal batteries(ASSMBs)are closely related to the Na^(+)coordination environment.Herein,an electrostatic ...Ion migration capability and interfacial chemistry of solid polymer electrolytes(SPEs)in all-solid-state sodium metal batteries(ASSMBs)are closely related to the Na^(+)coordination environment.Herein,an electrostatic engineering strategy is proposed to regulate the Na^(+)coordinated structure by employing a fluorinated metal–organic framework as an electron-rich model.Theoretical and experimental results revealed that the abundant electron-rich F sites can accelerate the disassociation of Na-salt through electrostatic attraction to release free Na^(+),while forcing anions into a Na^(+)coordination structure though electrostatic repulsion to weaken the Na^(+)coordination with polymer,thus promoting rapid Na^(+)transport.The optimized anion-rich weak solvation structure fosters a stable inorganic-dominated solid–electrolyte interphase,significantly enhancing the interfacial stability toward Na anode.Consequently,the Na/Na symmetric cell delivered stable Na plating/stripping over 2500 h at 0.1 mA cm^(−2).Impressively,the assembled ASSMBs demonstrated stable performance of over 2000 cycles even under high rate of 2 C with capacity retention nearly 100%,surpassing most reported ASSMBs using various solid-state electrolytes.This work provides a new avenue for regulating the Na^(+)coordination structure of SPEs by exploration of electrostatic effect engineering to achieve high-performance all-solid-state alkali metal batteries.展开更多
基金supported by the National Natural Science Foundation of China(No.52473213 and No.52203261)。
文摘Ion migration capability and interfacial chemistry of solid polymer electrolytes(SPEs)in all-solid-state sodium metal batteries(ASSMBs)are closely related to the Na^(+)coordination environment.Herein,an electrostatic engineering strategy is proposed to regulate the Na^(+)coordinated structure by employing a fluorinated metal–organic framework as an electron-rich model.Theoretical and experimental results revealed that the abundant electron-rich F sites can accelerate the disassociation of Na-salt through electrostatic attraction to release free Na^(+),while forcing anions into a Na^(+)coordination structure though electrostatic repulsion to weaken the Na^(+)coordination with polymer,thus promoting rapid Na^(+)transport.The optimized anion-rich weak solvation structure fosters a stable inorganic-dominated solid–electrolyte interphase,significantly enhancing the interfacial stability toward Na anode.Consequently,the Na/Na symmetric cell delivered stable Na plating/stripping over 2500 h at 0.1 mA cm^(−2).Impressively,the assembled ASSMBs demonstrated stable performance of over 2000 cycles even under high rate of 2 C with capacity retention nearly 100%,surpassing most reported ASSMBs using various solid-state electrolytes.This work provides a new avenue for regulating the Na^(+)coordination structure of SPEs by exploration of electrostatic effect engineering to achieve high-performance all-solid-state alkali metal batteries.
