Nickel-rich cathode material has received marked attention as an advanced cathode material, however, its inferior surface property limits the achievement of high performance in lithium-ion batteries. We propose the use of a bi-functional additive of triphenyl borate (TPB) for improvement of the safety and electrochemical performance of Ni-rich cathode materials. First, TPB removes residual lithium species from the Ni-rich cathode surface via chemical binding with anion part of residual lithium species, and effectively reduces swelling behavior of the cell. Second, TPB creates effective cathode−electrolyte interphase (CEI) layers on the electrode surface by an electrochemical reaction, and greatly enhances the surface stability of the nickel-rich cathode. This work demonstrate that a cell cycled with the TPB additive exhibits a remarkable retention of 88.6% at 60 °C after 100 cycles for an NCM721 cathode material. We suggest a working mechanism for TPB based on systematic analyses, including in-situ and ex-situ experiments.

富镍正极材料作为一种先进的正极材料受到了广泛的关注，但是，其劣质的表面性能限制了锂离子电池高性能的实现。我们建议使用硼酸三苯酯（TPB）的双功能添加剂来改善富镍阴极材料的安全性和电化学性能。首先，TPB通过与残余锂物质的阴离子部分化学键合从富镍阴极表面除去残余锂物质，并有效降低电池的溶胀行为。其次，TPB通过电化学反应在电极表面上形成有效的阴极-电解质中间相（CEI）层，并大大提高了富镍阴极的表面稳定性。这项工作表明，对于NCM721阴极材料进行100次循环后，用TPB添加剂循环的电池在60°C下表现出显着的88.6％的保留率。我们建议基于系统分析的TPB工作机制，包括原位和异位实验。