A New Structure Bipolar Plate for Vanadium Flow Battery

A pattern bipolar plate (BP) is designed to decrease the electrical contact resistance between the BP and carbon felt electrode (CFE) by increasing the BP's specific surface area through hot pressing the spherical crown pattern on the surface of the BP, and the carbon felt is pressed into the pattern by the stack tightening force. The contact area growth rate is 18.3% of a single cell which has 48cm2 active area. The areal specific resistance (ASR) of conventional BP and pattern BP is 1309 mΩ·cm2 and 946 mΩ·cm2 at 20% electrode compression ratio, the pattern plate is 27% lower than the conventional plate. In the single battery charge/discharge cycle test, battery assembled with the pattern BP shows a 1% higher EE than the conventional BP