Low-temperature performance of Li-ion batteries: The behavior of lithiated graphite

• Published in: Journal of power sources Vol. 282; pp. 235 - 240
• Main Authors: Senyshyn, A., Mühlbauer, M.J., Dolotko, O., Ehrenberg, H.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.05.2015
• Subjects: Capacity reduction; In operando studies; Li-ion battery; Low-temperature performance; Neutron powder diffraction; Low-temperature performance; Capacity reduction; In operando studies; Li-ion battery; Neutron powder diffraction
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2015.02.008

Safety issues along with the substantially reduced energy and power capabilities of Li-ion cells, operated at low temperatures, pose a technical barrier limiting their use in electric vehicles and aerospace applications. A combined in situ high-resolution neutron powder diffraction and electrochemical study on Li-ion cells of the 18650-type over a temperature range from 230 K to 320 K is reported with a focus on the graphite anode and the low temperature performance of the cell. Instead of a quasi-continuous behavior as observed at ambient temperatures, an anomalous behavior occurs upon discharge at low temperature, primarily reflected in the abrupt character of the LiC12 – to – graphite phase transformation and the unusual temperature dependence of the amount of LiC6. An instability of lithiated graphite phases at temperatures below 250 K is observed, which affects the performance of Li-ion batteries at low temperatures. [Display omitted] •Combined in operando electrochemical and neutron powder diffraction study at low temperatures.•Reduction of cell capacity along with an increase of the internal cell resistance.•Structural indications for anomalous behavior of lithium intercalation into graphite at low temperatures.•Quasicontinuous LiC12-to-C transition pathway breaks at low temperatures.•Anomalous temperature behavior of LiC6 (stage I) intercalated graphite.