Application of exfoliated graphene as conductive additive for lithium-ion secondary batteries

Abstract

We established that the application of exfoliated graphene as the conductive additive in the anode active material of the secondary battery was effective in improving the charge/discharge cycle characteristics compared to commonly used carbon materials, such as Ketjenblack and graphite. Exfoliated synthetic graphene produced using a biaxial independently controlled three-dimensional rotary ball mill has a unique shape. In order to uniformly disperse it in the electrode, while maintaining a flake shape thinner than graphene, we develop a dispersion technology using a wet process that utilizes a homogenizer and jet mill. Although the resistance component of the electrode synthesized by mixing exfoliated graphene with powdered silicon is greater than those of the other carbon materials, it is considered advantageous as a conductive additive because it ensures physical contact with the active material, even when the anode matrix disintegrates due to the rapid volume changes in silicon by repeated charge/discharge.