Temperature Dependent Life Cycle Analyses of Anodes from Coal-Derived Carbons

Abstract

Degradation of lithium-ion cells is generally manifested in active material loss (on either the negative or positive electrode), lithium inventory loss, or an increase in cell resistance.1 The underlying mechanisms resulting in said degradation are numerous and complex. For example, both the obvious growth of the solution electrolyte interface (SEI) or current collector dissolution may cause an increase in cell resistance over the lifetime of cell operation. The objective of this work is to utilize temperature dependency as a probe to elucidate and better understand the degradation of lithium-ion cells employing coal-derived graphite anodes. The coal derived materials are contrasted with traditional anode materials through coulombic efficiency vs. capacity retention comparisons, voltage slip analyses, and post cycling characterization at various temperatures. The behavior at temperature extremes is highlighted and emphasis is placed on quantifying the effect of temperature on the prominent degradation modes.References C. R. Birkl, M. R. Roberts, E. McTurk, P. G. Bruce, and D. A. Howey, J. Power Sources, 341, 373–386 (2017).