| 摘要 |
PROBLEM TO BE SOLVED: To provide a secondary battery excellent in a charge-discharge cycle life by preparing paste by performing the dry mixing of an active material, capable of storing and releasing lithium ions with carbon black so as to obtain a specific surface area according to a BET method, and by making a negative electrode by applying the paste to a collector or a film forming sheet. SOLUTION: Dry of an active material with carbon black is performed so as to obtain a specific surface area of 2.6-3.3 m2/g according to a BET method. Thereby, the active material suitably intertwines with the structure of the carbon black, and the adhesion of the carbon black to the active material is enhanced. Therefore, reduction in the contact area between the active material and the carbon black is prevented by the expansion and contraction of a power generation element in conjunction with the progress of charge-discharge cycles, so that the conductivity of a negative electrode can be maintained. A positive electrode 1 comprises positive electrode layers 5 bonded to both surfaces of a porous collector 4, and the negative electrode 2 comprises negative electrode layers 7 bonded to both surfaces of a porous collector 6. The power generation element is enclosed in a waterproof armoring material 11, and a positive electrode and negative electrode leads are made to come out. |
