Degradation of lithium ion batteries employing graphite negatives and nickel-cobalt-manganese oxide + spinel manganese oxide positives: Part 1, aging mechanisms and life estimation

• Published in: Journal of power sources Vol. 269; pp. 937 - 948
• Main Authors: WANG, John, PUREWAL, Justin, PING LIU, HICKS-GARNER, Jocelyn, SOUKAZIAN, Souren, SHERMAN, Elena, SORENSON, Adam, LUAN VU, TATARIA, Harshad, VERBRUGGE, Mark W
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 10-12-2014
• Subjects: Applied sciences; Charge; Degradation; Direct energy conversion and energy accumulation; Electric potential; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrode materials; Exact sciences and technology; Graphite; Lithium; Lithium-ion batteries; Materials; Monitors; Nickel; Ternary compound; Lithium ion batteries; Cobalt Oxides; Nickel Oxides; Electrode material; Capacity fade; Mechanism; Degradation; Lithium ion; Life model; Damaging; Cathode; Ageing; Lithium-ion; Durability; Secondary cell; LMO; Lifetime; Blended cathode; Deterioration; Spinels; Graphite; Capacitance; Manganese Oxides; NCM; Models
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2014.07.030

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.