Long cycle-life LiFePO_4/Cu-Sn lithium ion battery using foam-type three-dimensional current collector

摘要

To improve the cycle-life performance of LiFePO_4/Cu-Sn lithium ion battery, a new methodology using a foam-type three-dimensional current collector was investigated. By applying the three-dimensional nickel substrate for the negative electrode, instead of conventional copper foil, the cycle performance of the Cu-Sn electrode was improved. In addition, a heat treatment of the electrode was revealed to suppress the capacity decline drastically: the heat treated electrode showed the capacity above 400 mAh g~(-1) even after 50 cycles. A full-cell which combined the developed negative electrode and a positive electrode based on LiFePO_4 also showed a favorable cycle performance. Furthermore, a full-cell using aqueous slurry was prepared, and the cell exhibited an excellent cycle-life performance in which it maintained above 90% of the maximum capacity even at the 200th cycle.