| 摘要 |
PURPOSE: To provide a lithium secondary battery which obtains improving a charge/discharge life, by using a lithium metal containing powder of a boron system compound in a negative electrode, so as to prevent decreasing safety generated by repeating a charge/discharge. CONSTITUTION: By including a boron system compound in a negative electrode, depositing lithium is generated preferentially from a contact surface between powder of the boron system compound and a lithium metal, to grow a crystal with powder of the boron system compound serving as a nuleus even when deposited. From this fact, a uniform deposition form can be realized as a negative electrode main unit, to prevent easily generating branch-shaped lithium even when repeated a long period charge/discharge. As the negative electrode, foil of 150μm thickness, containing uniformly 30vol.% TiB2 powder of 20μm grain size in a lithium metal, is used. Even in the case of separating by forming branch-shaped lithium, by making contact with powder of the boron system compound, since reusing in a charge/discharge can be made, improving a charge/ discharge life can be realized. |
