| 摘要 |
PURPOSE:To provide a lithium secondary battery of a large charging/discharging capacity and of a high energy density. CONSTITUTION:Lithium oxalate (Li2C2O4) is added to one or two or all among a positive electrode including a sufficient quantity of lithium, a negative electrode comprising carbon material, and nonaqueous electrolyte. The upper limit value of the total addition quantity of the lithium oxalate is half the mole number of lithium quantity equivalent to irreversible capacity of the negative electrode carbon material. The lithium oxalate is oxidized (a) by charging in the first cycle to be decomposed into lithium ions and carbon dioxide. The lithium ions (b) generated by decomposition are reduced (c) in the negative electrode to be supplied for the irreversible capacity part, and all the lithium deintercalated from the positive electrode act as the irreversible capacity in charge and discharge after that. As a result, charging/discharging cycle characteristics and a discharging capacity of a lithium secondary battery are improved. |
