A proof-of-concept graphite anode with a lithium dendrite suppressing polymer coating

Dendritic Li deposition on graphite anodes of Li-ion batteries (LIBs) not only deteriorates the anode performance but also causes safety concerns. We demonstrate here a proof-of-concept graphite anode containing a polymer coating that effectively mitigates Li dendrite formation under harsh lithiatio...

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Bibliographic Details
Published in:	Journal of power sources 2018-12, Vol.406, p.63-69
Main Authors:	Luo, Jing, Wu, Chang-En, Su, Lin-Ya, Huang, Sheng-Siang, Fang, Chia-Chen, Wu, Yu-Shiang, Chou, Jackey, Wu, Nae-Lih
Format:	Article
Language:	eng
Subjects:	Fast-charge Graphite anode Lithium dendrite suppression Over-lithiation Polyvinylidene difluoride Safety
Online Access:	Get full text
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Summary:	Dendritic Li deposition on graphite anodes of Li-ion batteries (LIBs) not only deteriorates the anode performance but also causes safety concerns. We demonstrate here a proof-of-concept graphite anode containing a polymer coating that effectively mitigates Li dendrite formation under harsh lithiation conditions. It is shown that Li dendrites with dimensions ranging from a few tens nanometers to microns occur readily on granular graphite electrodes either under 20% over-lithiation at 0.2C or fast lithiation up to 10C rate. In contrast, the graphite anode with a conformal thin coating of high-polarity β-phase polyvinylidene difluoride (PVDF) on graphite particles exhibits dendrite-free Li plating under either condition. Moreover, the PVDF coated graphite anode exhibits substantially improved cycling stability with high Coulombic efficiencies under the Li-plating conditions. The rise of charge-transfer resistance due to over-lithiation is reduced. The proof of concept for adopting a dendrite-suppressing polymer coating on graphite anodes offers a new strategy for improving battery safety and renders more options for cell design in enhancing energy and power performances for the state-of-the-art LIBs. [Display omitted] •Graphite anode with lithium dendrite suppression polymer coating is demonstrated.•Li dendrites occur readily on graphite anode under over-lithiation and fast charge.•β-phase PVDF coating effectively suppresses Li dendrite formation on graphite.•β-phase PVDF coating reduces charge-transfer resistance rise upon over-lithiation.
ISSN:	0378-7753 1873-2755