Developing all-solid-state polymer electrolytes(SPEs) with high electrochemical performances and stability is of great importance for exploiting of high energy density and safe batteries. Herein, ether linkage and imi...Developing all-solid-state polymer electrolytes(SPEs) with high electrochemical performances and stability is of great importance for exploiting of high energy density and safe batteries. Herein, ether linkage and imidazolium ionic liquid(ILs) are incorporated into the multi-armed polymer backbone though the series and parallel way. The parallel polymeric ionic liquid(P-P(PEGMA-IM)) maximizes the synergistic effect of ILs and ether linkage, which endowed the material with low crystallinity and high flame retardancy. The P-P(PEGMA-IM) based P-SPE presents a high ionic conductivity of 0.489 m S/cm at 60°C, an excellent lithium-ion transference number of 0.46 and a wide electrochemical window of 4.87 V.The assembled lithium metal battery using P-SPE can deliver a capacity of 151 m Ah/g at 0.2 C, and the capacity retention ratio reaches 82% with a columbic efficiency beyond 99%. The overpotential of P-SPE based symmetric battery is 0.08 V, and there is no apparent magnifying even after 130 h cycling. This new design provides a new avenue for exploitation of advanced SPEs for the next-generation batteries.展开更多
基金supported by the National Natural Science Foundation of China(U1904216,U22A20141)the Natural Science Foundation of Changsha City(kq2208258)the Natural Science Foundation of Hunan Province(2022JJ20068)。
文摘锂金属被认为是下一代高能锂电池最有前途的负极材料之一.然而,锂的不均匀沉积和巨大的体积变化严重限制了锂金属阳极的实际应用.本文采用简单的熔融法制备了无枝晶的双骨架三维复合锂负极(Li-B-Sn).Li-B-Sn复合负极独特的双骨架结构由LiB纤维相和Li22Sn5相组成,有利于锂的均匀脱除和沉积,减小了体积变化,提高了Li-B-Sn负极的性能.在对称电池中,Li-B-Sn负极在10 mA cm^(-2)的大面积容量下实现了1100h的长循环寿命.此外,高负载的LiFePO_(4)正极(~11 mg cm^(-2))和Li-B-Sn复合负极组装的全电池表现出优异的电化学性能,在2 C循环430次后,容量保持率高达92.5%.基于Li-B-Sn复合负极的Li-S软包电池循环寿命超过30圈,表现出比基于Li-B负极的Li-S软包电池更好的循环稳定性.三维骨架设计为锂金属电池的实际应用带来了新思路.
基金National Natural Science Foundation of China (No. 51303083)the Natural Science Foundation of Jiangsu Province (No. BK20191293)the Fundamental Research Funds for the Central Universities (No. 30920021123) for financial support。
文摘Developing all-solid-state polymer electrolytes(SPEs) with high electrochemical performances and stability is of great importance for exploiting of high energy density and safe batteries. Herein, ether linkage and imidazolium ionic liquid(ILs) are incorporated into the multi-armed polymer backbone though the series and parallel way. The parallel polymeric ionic liquid(P-P(PEGMA-IM)) maximizes the synergistic effect of ILs and ether linkage, which endowed the material with low crystallinity and high flame retardancy. The P-P(PEGMA-IM) based P-SPE presents a high ionic conductivity of 0.489 m S/cm at 60°C, an excellent lithium-ion transference number of 0.46 and a wide electrochemical window of 4.87 V.The assembled lithium metal battery using P-SPE can deliver a capacity of 151 m Ah/g at 0.2 C, and the capacity retention ratio reaches 82% with a columbic efficiency beyond 99%. The overpotential of P-SPE based symmetric battery is 0.08 V, and there is no apparent magnifying even after 130 h cycling. This new design provides a new avenue for exploitation of advanced SPEs for the next-generation batteries.
