A comparative study of aqueous- and non-aqueous-processed Li-rich Li1.5Ni0.25Mn0.75O2.5 cathodes for advanced lithium-ion cells

Abstract

High-capacity Li-rich cathode materials are highlighted as next-generation cathode candidates for lithium-ion batteries (LIBs) owing to their superior specific capacity. Herein, we report the synthesis of a lithium-rich layered cathode material, Li_1.5Ni_0.25Mn_0.75O_2.5, by the sol–gel method. Based on sustainability concerns, a combination of carboxymethyl cellulose (CMC) and acrylic binder was applied as a binder with the addition of a small amount of phosphoric acid in the slurry during electrode processing. The electrode with the CMC–acrylic binder combination delivered a specific capacity of 219.5 mA h g⁻¹ at C/10 rate with a capacity retention of >97.5% after 100 cycles, which is comparable with that of the PVDF-based electrode (226.6 mA h g⁻¹, ∼95.4% capacity retention). Moreover, the aqueous-processed electrode exhibits better rate performance at high rates (1C and 2C). This work demonstrates that aqueous binders can be employed for the cathode formulations of next-generation LIBs, thus enabling a route for the processing of low-cost and long-cycle-life lithium-ion cells in an environment-friendly way.