Effect of particle size on lithium intercalation performance of graphite anode

Artificial graphite samples with different particle size ranging from 13 to 80 mum were prepared by sieving method. The lithium intercalation performances of these samples were investigated. The results showed that the particle size had distinct effect on lithium intercalation performances of graphite. When particle size of graphite decreased gradually from 80 mum to 13 mum, the irreversible capacity loss of graphite increased about 10%. However, the revesible capacity increased with the decrease of particle size until the latter reached 20 p,m with which the graphite had the highest capacity. When the particle size decreased from 20 mum, the reversible capacity decreased also. It suggested that neither large nor small graphite particle is suitable for reversible lithium intercalation. The medium graphite particles have the optimum reversible capacity. The Brunauer-Emmett-Teller (BET) surface area was measured and it increased with the decrease of particle size. This trend could explain the change of lithium intercalation performances of graphite with particle size.