Active material, nonaqueous electrolyte battery, battery pack and battery module
摘要
說明書
The subscript w in the general formula of Li2+wNa2?xM1yTi6?zM2zO14+δ for the composite oxide can vary within a range of 0≤w≤4 depending on the state-of-charge of the composite oxide. For example, according to a production method described below, a composite oxide in which the subscript w is 0 in the general formula described above can be manufactured. When the composite oxide in which the subscript w is 0 is incorporated in a nonaqueous electrolyte battery as the negative electrode active material, and the resulting nonaqueous electrolyte battery is charged, the value of w+2 is elevated to a value within a range of more than 2 and 6 or less. Alternatively, a composite oxide can also be synthesized in a raw material composition ratio set so that an Li amount in the formula, w+2, is within a range of more than 2 and 6 or less before the initial charge, for example, by the process described below. The active material for a battery containing the composite oxide having an Li amount, w+2, within a range of more than 2 and 6 or less before the initial charge can suppress the trapping of lithium ions in its structure during the initial charge-and-discharge, and as a result, the initial charge-and-discharge efficiency can be improved.
