Analysis of the intermediate states of an electrode slurry by electronic conductivity measurements

Abstract

The electronic resistance of composite electrodes for lithium-ion batteries has a non-negligible effect on the charge–discharge performance at high rates. In order to obtain an electrode with a high-rate performance it is important that conductive materials, such as acetylene black (AB), in the electrode slurry form a good electron conduction network. This study evaluated the electron conduction network of various electrode slurries made using different processes and with different solid contents using electronic conductivity measurements of the electrode slurries. The conductivity of the slurry showed a correlation with the rate performance. Depending on the production method and solid content, the conductivity of the slurry changed. The results suggest that the electron conduction network of the slurry is modified by collisions between the AB and active material particles during kneading and by stirring the slurry with excess solvent during dispersion. Measuring the conductivity of the slurry is expected to help determine the conditions of its manufacture.