Inducing and Understanding Pseudocapacitive Behavior in an Electrophoretically Deposited Lithium Iron Phosphate Li-Metal Battery as an Electrochemical Test Platform.

Our study has effectively employed electrophoretic deposition (EPD) using AC voltage to develop a lithium iron phosphate (LFP) Li-ion battery featuring pseudocapacitive properties and improved high C-rate performance. This method has significantly improved the battery's specific capacity, achieving an impressive 100 mAhg-1 at a 5 C discharge rate, which showcases its superior high-rate capability. Additionally, the battery displayed excellent reversibility during its performance cycles. These results confirm the EPD method's efficacy in improving LFP electrode performance, yielding notable improvements in cycling stability and high-rate capability. The enhanced capacity and high-rate performance of the electrophoretic-deposited LFP electrodes are largely due to the fast kinetics facilitated by pseudocapacitive behavior-induced charge storage and a high Li-ion diffusion constant measured in our EPD-deposited LFP electrodes. This underscores the practicality of our approach and the development of a fundamental test platform to investigate the pseudocapacitive charge storage mechanism in electrodes with typical battery-like behavior.