Additives for improving cycle life of non-aqueous rechargeable lithium batteries

摘要

The loss in delivered capacity (fade rate) after cycling non-aqueous rechargeable lithium batteries can be reduced by incorporating a small amount of an improved additive in the battery. Improved additives include boron trifluoride (BF3), fluoboric acid (HBF4), or complexes thereof. The invention is particularly suited to lithium ion batteries. Complexes comprising BF3 and dietyl carbonate or ethyl methyl carbonate can be prepared which are particularly effective additives. Preferably, the additive is dissolved in the electrolyte.