ion battery Understanding the Behavior of LiCoO Cathodes at Extended Potentials in Ionic Liquid-Alkyl Carbonate Hybrid Electrolytes

The current electrolyte composition makes it difficult to achieve lithium with high energy density-
Due to the unstable crystal structure of over 4 LiCoO2, Ion batteries based on LiCoO2 chemistry.
2 V vs Li/Li results in the decomposition of oxygen and electrolyte.
Therefore, the development of electrolyte may hopefully improve the performance, for example, if some favorable properties of ionic liquids can be introduced into the carbonated electrolyte system.
Here we report the use of a mixed electrolyte (HE) system with a LiCoO2 cathode and observe excellent electrical properties when circulating to 4. 4 V vs Li/Li+.
This extended potential range generates higher capacity through larger ion insertion/extraction and better structural stability.
The discharge capacity is 161 mAh/g (0.
7 lithium extraction) was observed in HE after 60 cycles, compared to 128 mAh/g in conventional electrolyte. The charge-
Compared with conventional electrolyte (LP30), discharge studies at extended potential also show that the capacity in HE remains better.
In order to confirm the origin of this behavior, the investigation confirmed that the formation of the surface film protected or delayed the phase transition of LiCoO2 under the extended potential.
In situ X-ray diffraction studies show that electrolyte combinations help to delay the possibility of single-phase formation in LiCoO2, and that the previous in situ X-ray diffraction studies show that at the end of 60 cycles, the structural degradation in HE is less than that in traditional electrolyte.
Therefore, we believe that future HE customization will provide an important step for high energy density lithium batteries.
(Render chart ).