posted on 2024-06-14, 12:33authored byXiaozhi Jiang, Fangyan Liu, Maohui Bai, Long Chen, Mengran Wang, Kun Zhang, Jiayi Yang, Bo Hong, Yang Ren, Yanqing Lai, Jie Li
A prevalent method to bolster the safety of lithium-ion
batteries
(LIBs) is through the deployment of phosphate-based electrolytes.
Nonetheless, an intrinsic challenge arises from the incompatibility
between phosphate components and graphite anodes, a phenomenon known
as coinsertion. To tackle this obstacle, we introduce a comprehensive
strategy that employs in situ thermal polymerization, leveraging a
flame-retardant solvent and a polymer matrix. This approach fosters
strong dipole–dipole interactions between phosphate molecules
and the polymer matrix, effectively alleviating the adverse impacts
on graphite anodes. This significant enhancement is validated through
in situ X-ray diffraction, X-ray photoelectron spectroscopy depth
profile analysis, and transmission electron microscopy imaging. Our
methodology facilitated stable lithium-ion operations within electrolytes
comprising 20% phosphate components in assembled NCM811|P-GPE|Gr pouch
cells, achieving a low-capacity decay rate of 0.0023% per cycle with
good flame-retardant characteristics. We believe this strategy heralds
new commercial prospects for incorporating phosphate-based solvents
in the creation of exceptionally safe LIBs.