Improving capacity and rate capability of Li-ion cathode materials through ball milling and carbon coating – Best practice for research purposes

Abstract Within battery research, there is an intense focus on design, synthesis and characterization of novel electrode materials. In order to function, an electrode material must exhibit a certain level of electronic conductivity to facilitate the electron transport in the battery. To increase the electronic conductivity of novel materials, post-synthesis treatments are often required in order to allow meaningful investigation of e.g. structural or morphological changes at deep charge/discharge. Such treatments often aim at particle size reduction and carbon coating. Thus, there is a great interest for general knowledge about the outcome of simple optimization strategies. Herein, we investigate how material purity, particle size, battery capacity and rate capability are affected by optimization via carbon coating and ball milling at various stages of the material preparation. We utilize Li3V2(PO4)3 as case material, and our findings reveal that short milling times and carbon coating provides the best result.