Su Wei, Wang Dongxiao, Li Yuanhang, Mao Huican, Wei Bingxin, Xu Shuyin, Lu Shigang, Guo Bingkun, Lyu Yingchun
Materials Genome Institute, Shanghai University, Shanghai 200444, China.
School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China.
ACS Nano. 2024 Sep 3;18(35):24541-24549. doi: 10.1021/acsnano.4c08836. Epub 2024 Aug 20.
Recharging primary batteries is of great importance for increasing the energy density of energy storage systems to power electric aircraft and beyond. Carbon fluoride (CF) cathodes are characterized by high specific capacity and energy density (865 mAh g and 2180 Wh kg, respectively). Preventing the crystallization of LiF with an intermediate and lowering the energy barrier from LiF to CF is expected to render the Li/CF battery reversible. In this study, taking the advantage of a high-voltage-stable all-fluorinated electrolyte containing the boron-based anion receptor tris(trimethylsilyl)borate (TMSB), a rechargeable Li/CF battery was realized with a reversible capacity of 465.9 mAh g and an energy density of 1183.9 Wh kg, approximately 53% of that in the first discharge. After the first discharge, the charge-discharge profile featured rechargeable characteristics. X-ray diffraction, soft X-ray absorption spectroscopy, pair distribution function analysis, and other measurements confirmed the generation and decomposition of Li-F and C-F bonds during cycling. Density functional theory calculations and nuclear magnetic resonance spectroscopy confirmed that TMSB serves as an anion carrier through the generation of a [TMSB-F] complex, facilitating the conversion reactions during cycling. This study demonstrated a facile and low-cost approach for realizing high-energy-density, reversible Li/CF batteries.
对一次电池进行充电对于提高储能系统的能量密度以驱动电动飞机及其他应用至关重要。氟化碳（CF）阴极具有高比容量和能量密度（分别为865 mAh g和2180 Wh kg）的特点。通过一种中间体防止LiF结晶并降低从LiF到CF的能垒有望使Li/CF电池可逆。在本研究中，利用含硼基阴离子受体三（三甲基硅基）硼酸酯（TMSB）的高压稳定全氟电解质，实现了一种可逆容量为465.9 mAh g、能量密度为1183.9 Wh kg的可充电Li/CF电池，约为首次放电时的53%。首次放电后，充放电曲线呈现出可充电特性。X射线衍射、软X射线吸收光谱、对分布函数分析及其他测量证实了循环过程中Li-F键和C-F键的生成与分解。密度泛函理论计算和核磁共振光谱证实TMSB通过生成[TMSB-F]配合物作为阴离子载体，促进了循环过程中的转化反应。本研究展示了一种实现高能量密度、可逆Li/CF电池的简便且低成本的方法。
