Active material, nonaqueous electrolyte battery, battery pack and battery module
摘要
說明書
The specific surface area of the positive electrode active material is preferably 0.1 m2/g to 10 m2/g. The positive electrode active material having a specific surface area of 0.1 m2/g or more can secure sufficient sites in which lithium ions can be inserted and extracted. The positive electrode active material having a specific surface area of 10 m2/g or less is easy to handle during industrial production, and can secure a good charge-and-discharge cycle performance.
The binder is added to bind the positive electrode active material with the current collector. Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine rubber, a polyacrylic acid compound, and an imide compound.
The conductive agent is as necessary added to improve the current collection performance, and to suppress the contact resistance between the positive electrode active material and current collector. Examples of the conductive agent include carbonaceous substances such as acetylene black, carbon black and graphite.
In the positive electrode layer, the blending ratios of the positive electrode active material and binder are preferably 80% by mass to 98% by mass, and 2% by mass to 20% by mass, respectively.
When the binder content is 2% by mass or more, sufficient electrode strength can be achieved. When the binder content is 20% by mass or less, the loading of the insulator in the electrode can be reduced, and thereby the internal resistance can be decreased.
