Additive for lithium-ion battery electrolyte—Benzotriazole

Lithium-ion battery market is mainly divided into three parts, consumer electronics, transportation and industrial storage. According to the statistics of RealLi Research, in 2016, consumer electronics products remained the largest market for lithium-ion batteries, accounting for 46.0% of the total, with the market share dropping below 50% for the first time. In recent years, with the development of the new energy automotive industry, the share of the transportation market represented by electric vehicles has rapidly risen to 38.3% in 2016.

The rapid development of new energy automotive industry, promoting the market demand for lithium-ion battery growth in electronic vehicles, but also led to the development of new materials in this area. Electrolyte is a key component for lithium-ion battery, its quality will directly affect the performance of lithium-ion batteries, but also to a certain extent, affect the safety of lithium-ion batteries.

Electrolyte is composed of solvent, lithium salt and additives, accounting for about 15% of the cost of lithium-ion batteries. At present, lithium salt is very sensitive to moisture, once the contact with water will react, resulting in gas production, battery bulging, worse cycling performance etc. In order to solve the above problems, a small amount of additives, such as film-forming additives, flame retardant additives, multi-functional additives, are added to improve the performance of lithium-ion battery.

Jongwook park et al ^[1] found that benzotriazole(BZTZ) as an additive can improve the electrochemical performance of 1 M LiPF6 EC / DMC (3/7) (v / v) electrolyte. The researchers compared the addition of 0.1 wt% and the performance of the electrolyte without BZTZ. The electrolyte without BZTZ decomposed at 5.1 V, whereas the electrolyte with BZTZ was decomposed at 5.6 V. In addition, BZTZ enables SEI film formation faster and more stable, which can also prevent PF6^- ion from decomposition.

With the enhancement of the energy density of lithium-ion batteries, the application of high voltage and electrode materials with high content of nickel, more and more functional additives will be used and will also promote the development of additive materials for electrolyte.

Reference:

[1] L. Hamenu, et al., Benzotriazole as an electrolyte additive on lithium-ion batteries performance, J. Ind. Eng. Chem. 2017,53,241-246.

Related links: Benzotriazole

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