On the Effect of Carbon Additives on the Porosity of Positive Electrodes Based on LiFePO4 for Lithium-Ion Batteries

Abstract

Using the small-angle neutron scattering method, the effect of conducting carbon additives (carbon black, graphene, and carbon nanotubes) on the porous structure of positive electrodes based on lithium iron phosphate (LiFePO₄) is studied. To separate scattering at closed pores from scattering at open pores, the electrode is wetted with a deuterated electrolyte, which makes it possible to compensate for the scattering at open pores. The used additives are found to change the electrode porosity to different extents and affect the wettability of the material both through a different efficiency of the incorporation of the initial material into pores and due to a change in the matrix of lithium iron phosphate.