| 摘要 |
PROBLEM TO BE SOLVED: To improve the conductivity of the whole of a positive electrode material layer, and to improve the ion mobility by including a specified weight ratio of graphite powder and acetylene black powder to be used as a conductive assistant in the positive electrode material layer while mixing with the lithium transition metal double oxide. SOLUTION: Mean grain diameter of the graphite powder included in the conductive assistant so as to improve the conductivity is desirably formed at 5-20 μm, and mean grain diameter of the acetylene black powder for improving the ion mobility is desirably formed at 0.02-0.05 μm. Content percentage of the acetylene black powder in relation to the total quantity is set at 55-70 wt.%. They are desirably used for the conductive assistant included in a positive electrode material layer laminated with a negative electrode material layer, which is mainly composed of carbon material such as amorphous carbon powder or graphite capable of storing and discharging lithium, through an electrode layer including the organic electrolyte while being mixed with the cobalt acid lithium. With this structure, internal resistance of a battery is lowered, and efficient discharging characteristic is improved. Mn, Fe, Ni or Ti is used as a transition metal of the double oxide except for Co. |
