Critical assessment of particle quality of commercial LiFePO4 cathode material using coin cells-a causal table for lithium-ion battery performance

LiFePO4 (LFP) is widely used as a cathode material for lithium-ion batteries (LIBs). While there exist many studies of the effect of particle size, purity, morphology, degree of agglomeration, and carbon coating on battery performance, it is not clear how these parameters are optimized in a commercial product. This paper aims at developing a causal table which relates the particle qualities to battery performance. A critical assessment of six commercial LFP products was performed in terms of material characteristics and the electrochemical performance of the corresponding button cells. One of the LFP samples with plate-like morphology, small particle size (0.15x0.4x0.6 mu m), and around 2.5 wt% carbon coating had the highest specific capacity (164.9 mAh g(-1) at 0.1 C) and rate capability (88.5 % at 1.5 C). The results are in general agreement with the relations captured in the causal table, verifying that it can be used to guide product development.