Graphitic carbon anode temperature excursions reflect crystallographic phase transitions in lithium-ion cells

JOURNAL OF POWER SOURCES

卷:293

Article

Srinivasan, Rengaswamy¹  Srinivasan, Lakshminarayan² 

[1] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA

[2] Stanford Univ, Dept Radiol, Neural Signal Proc Lab, Stanford, CA 94305 USA

关键词: Fast charging;    Anode temperature;    Phase transitions;    Graphitic carbon;    Lithiation;   

DOI  :  10.1016/j.jpowsour.2015.06.017

来源: Elsevier

【 摘 要 】

Surface temperature measurement of lithium-ion cells provides a limited view of internal physical processes during charging. Using a recently developed non-invasive battery internal temperature sensor, we now demonstrate that anode temperature reflects physically-based dynamics at the anode that were previously obscured by cell-surface measurements. First, using automated segmentation with a maximum-likelihood piecewise-linear statistical model, we show that features in the anode temperature reproducibly coincide with phase transitions into Stages IVd, IV and I of graphitic carbon lithiation at various charging rates. Second, we show that anode temperature peaks around 61% state of charge, intermediate between Stages II and I of the lithiated graphitic carbon. Third, we demonstrate a sharp and sustained increase in anode temperature at variable state of charge above 85%. These findings open the possibility for improved state-of-charge estimation and adaptive charging profiles that safely reduce charging time. (C) 2015 The Authors. Published by Elsevier B.V.

【 授权许可】

Free