Coin-type lithium secondary battery

摘要

A coin-type lithium secondary battery includes a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte. The negative electrode includes a negative electrode active material including a silicon alloy material, a conductive agent including a carbon material, and a binder. The silicon alloy material includes a phase A including a lithium-silicon alloy and a phase B including an intermetallic compound of a transition metal element and silicon. In the lithium-silicon alloy, a ratio of lithium atoms relative to silicon atoms is 2.75 to 3.65 in a 100% state-of-charge.

主权项

1. A coin-type lithium secondary battery comprising:
a positive electrode; a negative electrode; a separator interposed between the positive electrode and the negative electrode; and a non-aqueous electrolyte, the negative electrode including a negative electrode active material including a silicon alloy material, a conductive agent comprising a carbon material, and a binder, the silicon alloy material including a phase A comprising a lithium-silicon alloy and a phase B comprising an intermetallic compound of a transition metal element and silicon, and a ratio of lithium atoms relative to silicon atoms in the lithium-silicon alloy being 2.75 to 3.65 in a 100% state-of-charge, wherein: the positive electrode includes a positive electrode active material and the positive electrode active material is a composite oxide including lithium and manganese, and a charge cutoff voltage is set in a range of 2.8 to 3.3 V.