Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7736232 | Journal of Power Sources | 2014 | 12 Pages |
Abstract
We examine the aging and degradation of graphite/composite metal oxide cells. Non-destructive electrochemical methods were used to monitor the capacity loss, voltage drop, resistance increase, lithium loss, and active material loss during the life testing. The cycle life results indicated that the capacity loss was strongly impacted by the rate, temperature, and depth of discharge (DOD). Lithium loss and active electrode material loss were studied by the differential voltage method; we find that lithium loss outpaces active material loss. A semi-empirical life model was established to account for both calendar-life loss and cycle-life loss. For the calendar-life equation, we adopt a square root of time relation to account for the diffusion limited capacity loss, and an Arrhenius correlation is used to capture the influence of temperature. For the cycle life, the dependence on rate is exponential while that for time (or charge throughput) is linear.
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
John Wang, Justin Purewal, Ping Liu, Jocelyn Hicks-Garner, Souren Soukazian, Elena Sherman, Adam Sorenson, Luan Vu, Harshad Tataria, Mark W. Verbrugge,