Polyacrylonitrile electrolyte-based Li ion batteries

Polyacrylonitrile (PAN)-based electrolytes are appropriate for the fabrication of solid-state Li ion batteries. Prototype battery cells have been fabricated with spinel LiMn2O4 cathode and either a graphite or a petroleum coke anode. The propylene carbonate (PC)-containing electrolyte, PAN-EC/PC-LiPF6, is adequate for use with coke anode cells while the graphite anode cells require the non-PC-based electrolyte, PAN-EC/DPC-LiPF6, where EC is ethylene carbonate and DPC is dipropyl carbonate. Lower capacity fade and longer cycle life were observed in petroleum coke anode cells, which showed a specific energy of > 120 W h/kg and a cycle life of > 500 cycles at the C/3 rate. The capacity fade rate for coke/ LiMn2O4 cells has been found to be between 0.04 and 0.05% per cycle, about half of the fade observed in graphite/liMn(2)O(4) cells. (C) 1998 Elsevier Science Ltd. All rights reserved.