Effect of binder on the overcharge response in LiFePO4-containing cells

JOURNAL OF POWER SOURCES

卷:450

Article

Rago, Nancy Dietz¹  Li, Jianlin²  Sheng, Yangping²  Wood, David L., III²  Steele, Leigh Anna³  Lamb, Joshua³  Grosso, Christopher³  Fenton, Kyle³  Bloom, Ira¹ 

[1] Argonne Natl Lab, Chem Sci & Engn Div, Lemont, IL 60439 USA

[2] Oak Ridge Natl Lab, Energy & Transportat Sci Div, POB 2009, Oak Ridge, TN 37831 USA

[3] Sandia Natl Labs, Power Sources Technol Grp, Albuquerque, NM 87185 USA

关键词: Lithium-ion battery;    Overcharge;    Binders;    LiFePO4;   

DOI  :  10.1016/j.jpowsour.2019.227595

来源: Elsevier

【 摘 要 】

Two types of small pouch cells based on LiFePO4/graphite, one containing a N-methyl pyrrolidinone (NMP)-soluble binder, poly(vinylidene difluoride), and the other an aqueous-soluble binder, styrene-butadiene rubber/carboxymethylcellulose were systematically charged to 100, 120, 140, 160, 180, and 250% state of charge (SOC). The cells were then discharged to 3.0 V at room temperature before being disassembled for postmortem analysis. Microstructural changes in the anode associated with increasing SOC were more pronounced in the aqueous processed cells in comparison to the NMP-processed cells. Dendrite formation was observed on the aqueous-processed anode at 120% SOC, while the NMP-processed anode surface does not show dendrites until 250% SOC. Overall, the aqueous-processed anode surfaces displayed more evidence of microstructural degradation as a function of increasing SOC. In the NMP-processed cells, four organic compounds on the anode surface were found to show a dependence on SOC, while only two displayed a similar dependency in the aqueous-processed cells. The nature of the binder changed the number and composition of the species found at the anode.

【 授权许可】

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