| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium secondary battery negative electrode having high discharge capacity, low irreversible capacity, and superior cycle characteristic by forming negative electrode active material of specific amount of graphite and the rest, amorphous carbon containing phosphorus, oxygen, and inevitable impurity, and specifying the containing amount range of phosphorus and oxygen with respect to the whole amorphous carbon. SOLUTION: Negative electrode active material is formed of graphite with 5 to 50% (i.e., weight%, hereunder the same) and the rest, amorphous carbon containing phosphorus, oxygen, and unavoidable impurity, and the containing amount of phosphorus is in the range of 0.01 to 10%, and the containing amount of oxygen is in the range of 0.01 to 15% with respect to the whole amorphous carbon. The amorphous carbon 1 is made of larger carbon crystal elements 10, which is formed by decomposing and forming one part of the carbon crystal element constituting raw coke through heat. Lithium ions 2 are intercalation between the layers 13 of the layer structure of the carbon crystal elements 10, and lithium clusters 20 formed of lithium ions 2 are stored in cavities 11, formed between the mutual ends 12 of the carbon crystal elements 10, so as to obtain a lithium secondary battery negative electrode having superior cycle characteristic. |
