Dendrite-free Li metal deposition in all-solid-state lithium sulfur batteries with polymer-in-salt polysiloxane electrolyte
Dendrite-free Li metal deposition in all-solid-state lithium sulfur batteries with polymer-in-salt polysiloxane electrolyte
复制标题
采用聚合物盐聚硅氧烷电解质的全固态锂硫电池中的无枝晶锂金属沉积
DOI：
10.1016/j.ensm.2018.03.015
复制
发表时间：
2018-11-01
影响因子：
20.4
通讯作者：
Fan, Li-Zhen
中科院分区：
文献类型：
--
作者：
Chen, Long;Fan, Li-Zhen
固体聚合物电解质（SPE）由于其低挥发性、高安全性和抑制穿梭效应的能力，是高能量密度锂硫电池迫切需要的替代常规液体电解质。本文以双接枝聚硅氧烷共聚物、二（三氟甲烷磺酰）亚胺锂和聚偏氟乙烯为原料制备了盐中聚硅氧烷SPE，其离子电导率在25℃时达到7.8 × 10(-4) S cm（-1）。为了同时获得理想的离子电导率和较高的固体电解质力学性能，以醋酸纤维素为基体，制备了具有高离子电导率(4.0 × 10（-4) S cm(-1)）、高机械强度（6.8 MPa）、宽电化学稳定窗口（4.7 V vs. Li+/Li）、高室温离子转移数（0.52）的复合聚合物电解质（CPE）。此外，CPE还能有效抑制锂枝晶的生长和多硫化物的扩散。用CPE组装的硫锂电池在1C下表现出良好的室温循环性能，表明这种盐中聚合物聚硅氧烷基复合电解质膜可以应用于常温全固态硫锂电池。
Replacement of solid polymer electrolyte (SPE) to routine liquid electrolyte is highly desirable for high-energy-density lithium sulfur batteries due to its low volatility, high safety and the ability to suppress shuttle effect. Herein, a polymer-in-salt polysiloxane SPE was fabricated with bi-grafted polysiloxane copolymer, lithium bis(trifluoromethanesulfonyl) imide and poly(vinylidene fluoride), which shows higher ionic conductivity (7.8 x 10(-4) S cm(-1) at 25 degrees C). To obtain the satisfactory ionic conductivity and high mechanical property of solid electrolyte simultaneously, cellulose acetate matrix was combined as a rigid substrate to prepare composite polymer electrolyte (CPE) that possesses high ionic conductivity (4.0 x 10(-4) S cm(-1)), enhanced mechanical strength (6.8 MPa), wide electrochemical stability window (4.7 V vs. Li+/Li), and high ion transference number (0.52) at ambient temperature. In addition, the CPE effectively inhibits the growth of lithium dendrites and diffusion of polysulfides. The assembled lithium sulfur battery with CPE exhibits good room-temperature cycling performance at 1C, which indicates that such polymer-in-salt polysiloxane based composite electrolyte membranes can be applied to ambient temperature all-solid-state lithium sulfur batteries.