Robust solid/electrolyte interphase on graphite anode to suppress lithium inventory loss in lithium-ion batteries

Publication Type

Journal Article

Date Published

01/2017

Authors

DOI

Abstract

Lithium inventory loss is the most important reason for capacity decay of commercial lithium ion batteries(link is external). To suppress lithium inventory loss and prolong the battery cycle-life, sodium maleate (SM) is coated onto the surface of graphite active materials and act as the starting material for in-situ growth of SEI film. Microscopic studies show that the SM salt is uniformly dispersed on the graphite particles. The SM coating favors the formation of robust solid electrolyte interphase(link is external) (SEI) due to its abundant carboxyl group and improves the mechanical property due to the polymerization(link is external) between the unsaturated bonds. With 3.0 wt% SM coating, the first columbic efficiency, cycling stability and rate capability of the graphite anode(link is external) are simultaneously improved. Electrochemical impedance spectroscopy(link is external) (EIS) studies and scanning electron microscope(link is external) (SEM) observations show that continuous lithium deposit(link is external) on the graphite surface arising from the SEI instability during long-term electrochemical cycles is effectively suppressed. Cycle-life of the full cell assembled with LiFePO4 cathode and 3.0 wt% SM coated graphite anode is thus significantly prolonged.

Journal

Carbon

Volume

111

Year of Publication

2017

ISSN

00086223

Organization