Development of coin-type lithium-ion rechargeable batteries

We developed coin-type lithium-ion rechargeable batteries made of crystalline V₂O₅ for the cathode and pitch-based carbon for the anode. We optimized the capacity balance of cathode and anode materials. The batteries have a high operating voltage of about 2.7 V and excellent charge/discharge cycle characteristics. We also designed the batteries whose cathode potential is over 3 V versus lithium when the batteries are overdischarged to 0 V. Therefore, the batteries have excellent recovery characteristics even after overdischarge. The batteries have high energy density (about 100 Wh/l) which is about two times that of the coin-type NiCd batteries. It can serve as a memory backup power source with a single battery.