<p indent="0mm">Lithium slurry batteries are promising large-scale energy-storage devices because of their low cost, long life, and independent scalability of energy and power capabilities. Electrode slurry is the main component of lithium slurry batteries and its conductive and rheological properties play an important role in the electrochemical performance of batteries. Herein, the types and amounts of conductive additives on the conductivity and rheology of LiFePO<sub>4</sub>-based cathode slurry were investigated. By comparing the viscosity, suspension stability and conductivity of different cathode slurries, the 1.0 wt.% LFP–KB cathode slurry displayed a better electrochemical performance. Based on this cathode slurry, the lithium slurry batteries exhibited a stable cycle performance over 450 h. This work provides a guidance to select conductive additives for lithium slurry batteries.