Lithium-selenium (Li-Se) batteries have attracted increasing attentions in recent years because of their high energy density and theoretical capacity. One of the keys that influences the cycle stability of Se cathode is the formation of a stable cathode electrolyte interphase (CEI) film between the cathode material and electrolyte. In this work, we report utilizing tris(trimethylsilyl) borate (TMSB) as electrolyte additive to promote the formation of stable CEI film for enhanced Li-Se battery. The TMSB containing electron-deficient boron atoms easily adsorb electron-rich F⁻ and PF_x⁻ to form polyanionic groups, which suppress the formation of insulating LiF in the CEI film, promoting the conductivity and stability of the cathode. Furthermore, the TMSB adsorbing PF_x⁻ releases more active Li⁺ for reaction to improve the capacity. These largely improve the compatibility of the electrolyte and the electrode material interface, significantly reducing the interface impedance and increasing the rate capability. As the result, the system with 1 wt% TMSB exhibits a high specific discharge capacity of 462 mA h g ^–1 at 1 C after 500 cycles, showing 130% improvement for the cathode without TMSB. Our work here confirms that TMSB as electrolyte additive can effectively improve the electrochemical performance of Li-Se batteries.

近年来，锂硒（Li-Se）电池因其高能量密度和理论容量而受到越来越多的关注。影响硒正极循环稳定性的关键之一是在正极材料和电解质之间形成稳定的正极电解质中间相（CEI）膜。在这项工作中，我们报告了利用硼酸三（三甲基甲硅烷基）酯（TMSB）作为电解质添加剂来促进稳定的 CEI 膜的形成，用于增强型 Li-Se 电池。含有缺电子硼原子的TMSB容易吸附富电子的F ^-和PF _x ^-形成聚阴离子基团，抑制CEI膜中绝缘LiF的形成，提高阴极的导电性和稳定性。此外，TMSB 吸附 PF_x ^-释放更多活性Li ⁺用于反应以提高容量。这些在很大程度上提高了电解质和电极材料界面的相容性，显着降低了界面阻抗并提高了倍率能力。结果，含有 1 wt% TMSB 的系统在 500 次循环后在 1 C 下表现出 462 mA hg ^–1的高比放电容量，表明没有 TMSB 的阴极提高了 130%。我们在这里的工作证实了 TMSB 作为电解质添加剂可以有效提高 Li-Se 电池的电化学性能。