Voltage hysteresis during lithiation/delithiation of graphite associated with meta-stable carbon stackings

Mercer, Michael and Peng, Chao and Soares, Cindy and Hoster, Harry and Kramer, Denis (2021) Voltage hysteresis during lithiation/delithiation of graphite associated with meta-stable carbon stackings. Journal of Materials Chemistry A, 9 (1). pp. 492-504. ISSN 2050-7488

[img]
Text (voltage_hysteresis_metastable)
voltage_hysteresis_metastable.pdf - Published Version
Available under License Creative Commons Attribution.

Download (1MB)

Abstract

Cell voltage is a fundamental quantity used to monitor and control Li-ion batteries. The open circuit voltage (OCV) is of particular interest as it is believed to be a thermodynamic quantity, free of kinetic effects and history and, therefore, “simple” to interpret. Here we show that the OCV characteristics of graphite show hysteresis between charge and discharge that do not solely originate from Li dynamics and that the OCV is in fact history dependent. Combining first-principles calculations with temperature-controlled electrochemical measurements, we identify a residual hysteresis that persists even at elevated temperatures of greater than 50 °C due to differences in the phase succession between charge and discharge. Experimental entropy profiling, as well as energies and volume changes determined from first-principles calculations, suggest that the residual hysteresis is associated with different host lattice stackings of carbon and is related to Li disorder across planes in stage II configurations.

Item Type:
Journal Article
Journal or Publication Title:
Journal of Materials Chemistry A
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1600
Subjects:
ID Code:
150371
Deposited By:
Deposited On:
04 Jan 2021 13:05
Refereed?:
Yes
Published?:
Published
Last Modified:
26 Jan 2021 12:50