The solid- state reaction was employed to obtain a lithium salt, lithium bis (oxalato)borate (LiBOB). The best temperature range for preparing LiBOB is from 240 to 280 degrees C. The resulting LiBOB was employed in lithium- ion cells as an electrolyte, and the cells have been observed to perform satisfactorily. At 0.5 and 1C discharge rates, the capacity of the cell with LiBOB electrolyte was almost the same as that of the cell with LiPF6 electrolyte. At 55 degrees C the capacity retention of the cell using the LiBOB electrolyte was much higher than that of the cell using the LiPF6 electrolyte. (c) 2005 The Electrochemical Society.