Functional polyimide binder for high-nickel, high-voltage cathode materials of lithium rechargeable batteries
발표자
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초록
내용
Ni-rich layered oxides such as LiNi0.8Co0.1Mn0.1O2(NCM811) are appealing as promising high-capacity cathode materials. The reversible capacity can be charged with a voltage higher than 4.2 V of a conventional battery. But it is difficult to manufacture due to the unstable cathode-electrolyte interface and structural degradation. Herein, we report the combination of NCM811 with non-aqueous functional polyimide binder to imparts enhanced thermal stability and stable interface originating from insitu building-up of surface protective polyimide layer at cathode through monodentate metalcarboxylatechemical bonds during slurry preparation, which permits to charge to 4.4 V despite incommercial electrolyte without additive. It can be charged up to 4.4 V in commercial electrolyte conditions, suppresses metal dissolution and cathodic decomposition, creates a reversible capacity higher than 200 mAhg-1, and provides non-combustible properties unlike conventional binders, enabling stable operation.