High Power Battery Electrodes Using Nanoporous V₂O₅/Carbon Composites

Nanoporous composite electrodes for lithium ion batteries were successfully fabricated by coating porous carbon with V 2 O 5 gel, and their high rate capability was demonstrated. The porous carbons prepared by using SiO 2 colloidal crystals as templates exhibited ordered three dimensionally interconnected pores. The porous carbons were immersed in V 2 O 5 sol under reduced pressure repeatedly to obtain V 2 O 5 /carbon composites. The nanoporous V 2 O 5 /carbon composites thus obtained exhibited large capacity of more than 100 mAh (g-composite) -1 and good rate capability of 80% at 5.0 A (g-composite) -1 . The good performance is explained by electric double layer capacitance of large surface area and high rate lithium insertion to V 2 O 5 gel. According to a calculation, very high-power energy sources with 177 mAh (g-composite) -1 at 100 A (g-composite) -1 are expected by using the nanoporous composite electrodes.