| 摘要 |
PROBLEM TO BE SOLVED: To restrain characteristic deterioration caused by heat by, including a material for absorbing hydrogen on the inside of a battery. SOLUTION: A lithium oxide base positive electrode material becomes high oxidation state when lithium is extracted by charge and turns into a state which easily releases oxygen. When a battery is charged to high voltage, if hydrogen exists within the battery, the hydrogen reacts with the positive electrode material to produce water, and this causes the characteristic deterioration of the battery. A lithium secondary battery having an organic electrolyte and a carbon material as the constituting element forms a film on a negative electrode by the decomposition of the electrolyte in the initial charge, and since hydrogen is generated as a by-product, it is necessary to remove the hydrogen. Therefore, a material for absorbing hydrogen is preferably placed on the inside or the surface of a positive electrode or a negative electrode, or in the top space of the battery. As the material for absorbing the hydrogen, a hydrogen storage alloy can be used. In this case, the equilibrium pressure of hydrogen absorption at 25 deg.C of the hydrogen absorbing alloy is preferably 0.8 atm or less. |
