Enhancing the high-rate performance of LiFePO4 batteries using carbonized-filter paper as an interlayer

The rate performance of LiFePO4 batteries is improved by inserting a carbon interlayer, which is synthesized by a simple and cheap pyrolysis of the filter paper commonly used in the laboratories. The specific capacity of the LiFePO4 batteries at low current density is only slightly improved after the introduction of the carbon interlayer, while the specific capacity at high current density is greatly enhanced with a specific capacity of 90 mA h g(-1) and 76 mA h g(-1) at 10 C and 20 C, respectively, compared to a specific capacity of 17 mA h g(-1) and 8 mA h g(-1) of LiFePO4 batteries without a carbon interlayer. The improved electrochemical performance is attributed to the porous architecture of the carbon interlayer, serving as a conductive skeleton, largely reducing the charge transfer resistance.