Polyethylene oxide(PEO)-based solid polymer electrolytes are considered as promising material for solidstate sodium metallic batteries(SSMBs).However,their poor interfacial stability with high-voltage cathode limits t...Polyethylene oxide(PEO)-based solid polymer electrolytes are considered as promising material for solidstate sodium metallic batteries(SSMBs).However,their poor interfacial stability with high-voltage cathode limits their application in high-energy–density solid-state batteries.Herein,a uniform,sulfur-containing inorganic–organic composite cathode–electrolyte interphase layer was in situ formed by the addition of sodium polyvinyl sulfonate(NaPVS).The 5 wt%NaPVS-Na_(3)V_(2)(PO_(4))_(3)(NVP)|PEOsodium hexauorophosphate(NaPF6)|Na battery shows a higher initial capacity of 111.2 mAh.g^(-1)and an ultra-high capacity retention of 90.5%after 300 cycles.The 5 wt%NaPVS-Na_(3)V_(2)(PO_(4))_(2)F_(3)(NVPF)|PEO-NaPF_(6)|Na battery with the high cutoff voltage of 4.2 V showed a specific discharge capacity of 88.9 mAh.g^(-1)at 0.5C for 100 cycles with a capacity retention of 79%,which is much better than that of the pristine-NVPF(PR-NVPF)|PEO-NaPF_(6)|Na battery(33.2%).The addition of NaPVS not only enhances the diffusion kinetics at the interface but also improves the rate performance and stability of the battery,thus bolstering its viability for high-energy applications.In situ phase tracking further elucidates that NaPVS effectively mitigates self-discharge induced by the oxidative decomposition of PEO at high temperature.This work proposes a general strategy to maintain the structural stability of the cathode–electrolyte interface in PEO-based high-performance SSMBs.展开更多
基金supported by the Natural Science Foundation of China(No.22109079)the Natural Science Foundation of China(No.21973008)+2 种基金the Natural Science Foundation of China(No.22179010)the National Key R&D Program of China(No.2021YFB2400200)Taishan Scholars of Shandong Province(No.tsqnz20231212)。
文摘Polyethylene oxide(PEO)-based solid polymer electrolytes are considered as promising material for solidstate sodium metallic batteries(SSMBs).However,their poor interfacial stability with high-voltage cathode limits their application in high-energy–density solid-state batteries.Herein,a uniform,sulfur-containing inorganic–organic composite cathode–electrolyte interphase layer was in situ formed by the addition of sodium polyvinyl sulfonate(NaPVS).The 5 wt%NaPVS-Na_(3)V_(2)(PO_(4))_(3)(NVP)|PEOsodium hexauorophosphate(NaPF6)|Na battery shows a higher initial capacity of 111.2 mAh.g^(-1)and an ultra-high capacity retention of 90.5%after 300 cycles.The 5 wt%NaPVS-Na_(3)V_(2)(PO_(4))_(2)F_(3)(NVPF)|PEO-NaPF_(6)|Na battery with the high cutoff voltage of 4.2 V showed a specific discharge capacity of 88.9 mAh.g^(-1)at 0.5C for 100 cycles with a capacity retention of 79%,which is much better than that of the pristine-NVPF(PR-NVPF)|PEO-NaPF_(6)|Na battery(33.2%).The addition of NaPVS not only enhances the diffusion kinetics at the interface but also improves the rate performance and stability of the battery,thus bolstering its viability for high-energy applications.In situ phase tracking further elucidates that NaPVS effectively mitigates self-discharge induced by the oxidative decomposition of PEO at high temperature.This work proposes a general strategy to maintain the structural stability of the cathode–electrolyte interface in PEO-based high-performance SSMBs.
