Better cycle stability and rate capability of high-voltage LiNi0.5Mn1.5O4 cathode using water soluble binder

Abstract

5V LiNi0.5Mn1.5O4 (LNMO) cathodes are prepared using carboxymethyl chitosan (CCTS) as a water soluble binder and carbon coated aluminum foils (CAl) as current collector in Li-ion batteries (LIBs). CCTS exhibits an electrochemical oxidation potential as high as 5.0V. The electrochemical performance of LNMO cathode with CCTS binder is investigated and compared with the commercial non-aqueous polyvinylidene difluoride (PVDF). CCTS-CAl-LNMO electrode shows higher capacity retention (95.8%) than that of PVDF-CAl-LNMO (92.9%) and PVDF-Al-LNMO (88.52%) after 100 cycles. And, CCTS-CAl-LNMO electrode exhibits better rate capability than PVDF-CAl-LNMO, and PVDF-Al-LNMO, retaining specific capacity of 95.8mAhg−1 at 10C rate, only 87.6mAhg−1 and 1mAhg−1 for PVDF-CAl-LNMO, and PVDF-Al-LNMO, respectively. This approach can also be extended its use to other cathode materials such as LiNi1/3Co1/3Mn1/3O2 (NCM).