Hybrid Cathode of LiFePO4 and Activated Carbon Prepared with a Porous Al Current Collector and Its Battery Performance

Abstract

In order to improve both energy and power densities while durability of the battery is maintained, a layer of LiFePO4 layer which has characteristic of high energy density is formed on one side of the Al current collector and a layer of activated carbon which has characteristic of high power density were formed on the other side of the Al current. The full cell is constructed with hybrid cathode and graphite anode (Fig. 1). When high current densities are used in the discharging process of the full cell, the discharging reaction occurs mainly at the part of activated carbon in the hybrid cathode. After discharging, Li ions which are doped in the activated carbon move to the LiFePO4 layer (energy transfer from activated carbon to LiFePO4 electrode) until the electrode potentials of the activated carbon and LiFePO4 layers are equal. Therefore, the hybrid cathode can combine both high power and energy densities. Fig. 1 schematic drawing of a full cell of hybrid cathode/graphite anode. Figure 1