Tris(trimethylsilyl) borate

Clear colorless liquid

Tris(trimethylsilyl) borate is used as intermediate of organic synthesis and additive of lithium battery electrolyte.

Tris (trimethylsilyl) borate (TMSB) has been investigated as a protective cathode additive for increasing the cycle performance of several high-voltage cathode materials, including LiMn2O4 (4.5 V), LiNi_0.5Co_0.2Mn_0.3O₂ (4.4 V), LiNi_0.5Mn_1.5O₄ (4.9 V) and layered lithium-rich oxide cathode Li[Li_0.2Mn_0.54Ni_0.13Co_0.13]O₂ (4.8 V). TMSB can also be applied as an effective electrolyte additive to raise the cycle life of LiMn2O4 and LiFePO4 cathode Li-ion batteries at 55 °C. Compared with tris(trimethylsilyl)phosphate (TMSP), the CEI film generated from TMSB, which contains B and Si-rich compounds, shows a better ability to restrain the growth of interfacial resistance during cycling. The results reveal that the TMSB additive is easy to complex with Li⁺ ions, thus weakening the intermolecular force between Li+ ions and ethylene carbonate solvent, which is beneficial for the cycle performance. Besides, the changed Li+ solvation structure results in a thin and dense CEI film containing compounds with Si–O and B–O bonds, which favors the transfer of Li+ ions[1–2].

[1] Yan Chunfeng . “Tris(trimethylsilyl) borate as an electrolyte additive for high-voltage lithium-ion batteries using LiNi1/3Mn1/3Co1/3O2 cathode.” Journal of Energy Chemistry 25 4 (2016): Pages 659-666.
[2] Jie Wang . “Adjusting the solvation structure with tris(trimethylsilyl)borate additive to improve the performance of LNCM half cells.”Journal of Energy Chemistry 67 (2022): Pages 55-64.