Effects of anode active materials to the storage-capacity fading on commercial lithium-ion batteries

• Published in: Journal of power sources Vol. 174; no. 2; pp. 484 - 492
• Main Authors: Kwak, Gunho, Park, Jounghwan, Lee, Jinuk, Kim, Sinja, Jung, Inho
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 06.12.2007; Elsevier Sequoia
• Subjects: Applied sciences; Artificial graphite; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Exact sciences and technology; Lithium-ion battery; Natural-like graphite; Solid electrolyte interphase; Storage-capacity fade; Lithium-ion battery; Solid electrolyte interphase; Natural-like graphite; Artificial graphite; Storage-capacity fade; Natural graphite; Charge storage; Differential scanning calorimetry; Scanning electron microscopy; Anode; Solid electrolyte; Secondary cell; Binders; Lithium battery; Infrared spectrometry; Storage capacity; Vinylidene fluoride polymer; X ray diffractometry; Impedance; Passivation
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2007.06.169

Thermal storage of prismatic Li-ion cell with different types of anodes has been performed at 60 °C for 15 days to 30 days. The results were compared for two anodes: natural-like graphite (NLG) with styrene–butadiene rubber (SBR, 2.5 wt.%) binder and artificial graphite (AG) with polyvinylidene fluoride (PVdF, 6 wt.%) as binder. The storage-capacity fading behavior of the commercial Li-ion cell was studied by dissection the storage cells and analyzing their electrodes and solid electrolyte interphase (SEI), allows lithium-ion transfer but prevents electron migration using SEM, DSC, FT-IR, XRD and impedance analysis. Side-reaction and transformation of the passivation film on NLG anode contributed the capacity loss. Self-discharge of NLG cell due to high specific surface area was one of the main factors for capacity fading. Impedance analysis revealed that the interfacial resistance at NLG anode was larger than that of the AG anode. The increase of lithium alkylcarbonate and lithium carbonate due to reductive decomposition of electrolyte with storage time decreased the charge and increased the interfacial resistance.