High energy density li||The stability of the LiCoO2 battery is severely limited by the instability of the cathode electrolyte interface (CEI) at high and high temperatures. 
Figure 1Electrochemical performance studies.
Ma Jianmin, Hunan UniversityBy using a 2,4,6-tris(3,4,5-trifluorophenyl) borooxyborate (TTFPB) additive with low oxidation potential, a mechanically and thermally stable CEI with abundant LiBXOY and LIF inorganics was proposed. Due to its unique O-B-O covalent backbone and low solubility, the LiBBxoY outer layer can improve the mechanical strength and thermal stability of CEI, and inhibit the dissolution of CEI. In addition, the abundance of LIF species within the CEI further improves its mechanical strength and thermal stability. 
Figure 2Characterization of the licoo2 electrode after cycling.
Thanks to the tailor-made protection of CEI, the cleavage and regeneration of CEI as well as the irreversible phase change of the cathode are effectively mitigated, and the oxidative decomposition of the electrolyte is also significantly inhibited at high voltage temperatures. Therefore, the Li|| of an electrolyte containing TTFPB is usedThe licoo2 battery achieves excellent cycling performance at 46/4.After 200 150 cycles at 7 V, the capacity retention rate was 919% and 740%。In addition, this battery has excellent high-temperature performance, with a capacity retention rate of 78 after 150 100 cycles at 50 701 %/73.6 %。
Figure 3CEI analysis.
mechanically and thermally stable cathode electrolyte interphase enables high-temperature, high-voltage li||licoo2 batteries. angewandte chemie international edition 2023. doi: 10.1002/anie.202315608