Enhanced electrochemical properties of a natural graphite anode using a promising crosslinked ionomer binder in Li-ion batteries

Abstract

We prepared a waterborne crosslinked ionomer binder (c-Li-PSBM) with a crosslinking structure, and used it in a graphite anode for Li-ion batteries. We employed a low binder content of 1.5% and did not use any conductive additive in the anode. The c-Li-PSBM binder formed a strong interaction with graphite particles and facilitated the release of more free Li⁺ upon lithiation/delithiation leading to enhanced electrochemical properties, including cycling, electrochemical impedance spectroscopy and rate performances, compared to SBR. The cycling performance of the soft-package Li-ion battery with the c-Li-PSBM binder presents a retention of 85.2%, compared to 82.9% for that with SBR after 300 cycles at a rate of 1C. The rate capacity retention of soft-package batteries with the c-Li-PSBM binder is obviously higher than that with SBR, especially at high rates of 2C and 3C. It is believed that this novel c-Li-PSBM has significant potential for further commercial application in graphite anodes for Li-ion batteries.