Method for predicting discharge capacity and operating voltage of

Abstract

A method of determining the charge and/or discharge capacities of non-aqueous batteries with an operating voltage of about 4 volts, is provided including determining an inverse molar susceptibility value at each of a plurality of different temperatures for a plurality of lithium manganese spinel oxide cathode materials having different respective Mn valencies; plotting the inverse molar susceptibility values against temperatures for each of the plurality of lithium manganese spinel oxide cathode materials; determining values of at least one of two paramagnetic parameters, Weiss temperature and effective magnetic moment, by obtaining the temperature dependence of the above inverse molar susceptibility from a plot derived from the Curie-Weiss law, the Weiss temperature corresponding to a temperature value extrapolated to a zero point of the inverse molar susceptibility and the effective magnetic moment being obtainable from the gradient value of the plot; producing plural rechargeable lithium batteries in which lithium manganese spinel oxides with well-defined Mn valencies are used as cathode materials, and finding at least one of the charge or discharge capacities around 4V for each of the batteries; providing at least one correlation curve between the above-found charge and/or discharge capacities and the above-found at least one paramagnetic parameter value; and obtaining charge and/or discharge capacities for a rechargeable lithium battery containing a lithium manganese spinel oxide whose charge and/or discharge capacities are being sought from the at lest one determined paramagnetic parameter value using the at least one correlation curve. A method of determining the charge and/or discharge capacities of non-aqueous batteries with an operating voltage of about 4 volts, is also provided which includes determining a spontaneous magnetization value for each of a plurality of lithium manganese spinel oxide cathode materials having a different respective Mn valency by determining a magnetization value of each of a plurality of magnetic fields at a constant temperature to obtain and thereafter use a correlation curve.