In-situ polymerized lithium polyacrylate (PAALi) as dual-functional lithium source for high-performance layered oxide cathodes

In this paper, a novel route using lithium polyacrylate (PAALi) as dual-functional lithium source was developed to produce layered oxide cathodes. The PAALi was in-situ polymerized on the surface of Ni1/3Co1/3Mn1/3(OH)2 precursor. By means of spray drying, spherical powders composed of PAALi wrapped around the precursor were prepared. The organic compound PAALi can function as a particle size control agent as well as the highly dispersed lithium source in the proposed route. It can transform to carbon coating layers during pre-heat treatment at 450 °C under inert atmosphere. Those carbon coating layers not only significantly reduce agglomeration of particles and limit growth of the particle size, but also provide enough inner voids and paths after the subsequent sintering at 900 °C. The produced layered cathodes can deliver capacity retention of 84.4% after 200 cycles at 1C and a capacity of 110.5 mA h g−1 at 10C. In comparison, the sample prepared with traditional lithium source only delivers capacity retention of 63.0% after 200 cycles at 1C and 70.9 mA h g−1 at 10C. The proposed route using PAALi as lithium source is potentially generalized to a broad application in the preparation of high-performance electrode materials.