| 摘要 |
PURPOSE:To enhance the cycle characteristic of a non-aqueous secondary battery by preparing Li-containing Mn oxide used for pos. electrode active substance so as to have a specific surface area of 9.0-6.7m<2>/g as measured by BET method. CONSTITUTION:Mn oxide containing Li used to a positive electrode 7 has a specific surface area which becomes smaller than that of MnO2 as crude material when mixture of Li salt and MnO2 is subjected to heat treatment, depending upon the sort of MnO2 as material, share of Li content, heat treatment temp., etc. The specific surface area of this L-containing Mn oxide measured by BET method is restricted to 9.0-67.5m<2>/g, but a further restriction tot the range 9.0-61.5m<2>/g gives a proper specific surface area to enhance the charge/discharge cycle characteristic and provide a large discharge capacity as well as high endurance against overcharging. Selecting the particle sizes of the Li-containing MnO2 to under 20mum accomplishes uniform reactions of Li salt with MnO2, and remaining of a portion out of reaction can be suppressed. If the particle sizes of Li-containing MnO2 is below 20mum after the pos. electrode has undergone pressurized molding, Li can disperse evenly in the Mn solid phase, and movement of Li be suppressed during charging and discharging. Thus an enhanced cycle characteristic is obtained. |
