High-capacity thick cathode with a porous aluminum current collector for lithium secondary batteries

Abstract A high-capacity thick cathode has been studied as one of ways to improve the energy density of lithium secondary batteries. In this study, the LiFePO 4 cathode with a capacity per unit area of 8.4 m Ah cm −2 corresponding to four times the capacity of conventional cathodes has been developed using a three-dimensional porous aluminum current collector called “FUSPOROUS”. This unique current collector enables the smooth transfer of electrons and Li + -ions through the thick cathode, resulting in a good rate capability (discharge capacity ratio of 1.0 C/0.2 C = 0.980) and a high charge-discharge cycle performance (80% of the initial capacity at 2000th cycle) even though the electrode thickness is 400 μm. To take practical advantage of the developed thick cathode, conceptual designs for a 10-Ah class cell were also carried out using graphite and lithium-metal anodes.