Exploring the Limits of the Rapid-Charging Performance of Graphite as the Anode in Lithium-Ion Batteries
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Date
2022-01
Journal Title
Journal ISSN
Volume Title
Publisher
The Electrochemical Society
Abstract
Graphite is, in principle, applicable as a high-power anode in lithium-ion batteries (LIBs) given its high intralayer lithium diffusivity at room temperature. However, such cells are known to exhibit poor capacity retention and/or undergo irreversible side reactions including lithium plating when charged at current rates above ∼2 C (∼740 mA g−1). To explore the inherent materials properties that limit graphite anodes in rapid-charge applications, a series of full-cells consisting of graphite as the anode and a standard Li[Ni0.8Mn0.1Co0.1]O2 (NMC811) cathode was investigated. Instead of a conventional cathode-limited cell design, an anode-limited approach was used in this work to ensure that the overall cell capacity is only determined by the graphite electrode of interest. The optimized N:P capacity ratio was determined as N/P = 0.67, enabling stable cycling across a wide range of charging rates (4–20 C) without inhibition by the NMC811 cathode. The results show that unmodified, highly crystalline graphite can be an excellent anode for rapid-charge applications at up to 8 C, even with a standard electrolyte and NMC811 cathode and in cells with 1.0 mAh cm−2 loadings. As a rule, capacity and specific energy are inversely proportional to crystallite size at high rates; performance can likely be improved by electrolyte/cathode tuning.
Description
Keywords
graphite anode lithium ion batteries
Citation
Xu, W., Welty, C., Peterson, M. R., Read, J. A., & Stadie, N. P. (2022). Exploring the limits of the rapid-charging performance of graphite as the anode in lithium-ion batteries. Journal of The Electrochemical Society, 169(1), 010531.