NEGATIVE ELECTRODE FOR NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY AND NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY COMPRISING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a non-aqueous electrolyte secondary battery with a high capacity and excellent cycle characteristics by suppressing degradation of battery characteristics accompanying an expansion of an alloy material in a negative electrode using the alloy material and a graphite material.

SOLUTION: A negative electrode for a non-aqueous electrolyte secondary battery includes graphite and at least one alloy material capable of electrochemically absorbing and desorbing Li. The alloy material includes an A phase composed mainly of Si and a B phase made of a metallic chemical compound of at least one transition metal element and Si. At least one of the A phase and the B phase includes a microcrystalline or amorphous region. The weight percentage of the A phase relative to the total weight of the A phase and the B phase is greater than 40% and not greater than 95%. The weight percentage of the graphite relative to the total weight of the alloying material and the graphite is not less than 50% and not greater than 95%.

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