摘要 |
Provided are novel negative electrodes for use in lithium ion cells. The negative electrodes include one or more high capacity active materials, such as silicon, tin, and germanium, and a lithium containing material prior to the first cycle of the cell. In other words, the cells are fabricated with some, but not all, lithium present on the negative electrode. This additional lithium may be used to mitigate lithium losses, for example, due to Solid Electrolyte Interphase (SEI) layer formation, to maintain the negative electrode in a partially charged state at the end of the cell discharge cycle, and other reasons. In certain embodiments, a negative electrode includes between about 5% and 25% of lithium based on a theoretical capacity of the negative active material. In the same or other embodiments, a total amount of lithium available in the cell exceeds the theoretical capacity of the negative electrode active material.
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