Polarity-tuned Gel Polymer Electrolyte Coating of High-voltage LiCoO2 Cathode Materials
Cited 0 times inCited 0 times in
- Polarity-tuned Gel Polymer Electrolyte Coating of High-voltage LiCoO2 Cathode Materials
- Park, Jang-Hoon; Cho, Ju-Hyun; Kim, Jong-Su; Shim, Eun-Gi; Lee, Yun-Sung; Lee, Sang-Young
- Lithium-ion batteries; High-voltage lithium cobalt oxide; Polarity; Gel polymer electrolyte coating; Polyimide; Ethylene-vinyl acetate copolymer
- Issue Date
- 전기화학회지, v.14, no.2, pp.117 - 124
- We demonstrate a new surface modification of high-voltage lithium cobalt oxide (tex:\small\textstyle$LiCoO_2$) cathode active materials for lithium-ion batteries. This approach is based on exploitation of a polarity-tuned gel polymer electrolyte (GPE) coating. Herein, two contrast polymers having different polarity are chosen: polyimide (PI) synthesized from thermally curing 4-component (pyromellitic dianhydride/biphenyl dianhydride/phenylenediamine/oxydianiline) polyamic acid (as a polar GPE) and ethylene-vinyl acetate copolymer (EVA) containing 12 wt% vinyl acetate repeating unit (as a less polar GPE). The strong affinity of polyamic acid for tex:\small\textstyle$LiCoO_2$ allows the resulting PI coating layer to present a highly-continuous surface film of nanometer thickness. On the other hand, the less polar EVA coating layer is poorly deposited onto the tex:\small\textstyle$LiCoO_2$, resulting in a locally agglomerated morphology with relatively high thickness. Based on the characterization of GPE coating layers, their structural difference on the electrochemical performance and thermal stability of high-voltage (herein, 4.4 V) tex:\small\textstyle$LiCoO_2$ is thoroughly investigated. In comparison to the EVA coating layer, the PI coating layer is effective in preventing the direct exposure of tex:\small\textstyle$LiCoO_2$ to liquid electrolyte, which thus plays a viable role in improving the high-voltage cell performance and mitigating the interfacial exothermic reaction between the charged tex:\small\textstyle$LiCoO_2$ and liquid electrolytes.
Appears in Collections:
- ECHE_Journal Papers
can give you direct access to the published full text of this article. (UNISTARs only)
Show full item record
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.