Effect of MWCNT on the performances of the rounded shape natural graphite as anode material for lithium-ion batteries

Abstract

Multi-walled carbon nanotube (MWCNT) with bundle-type morphology was introduced as a new functional additive working as a particle connector or an expansion absorber in the anodes of lithium-ion batteries. By controlling the dispersion process, the MWCNT bundles were successfully divided and dispersed between the host particles. The composite anode consisting of rounded shape natural graphite and 2 wt.% of MWCNT exhibited the capacity of 300 mAh g -1 at 3 C rate and excellent cyclability. The well-dispersed MWCNT bundles made it possible to relieve the large strains developed at high discharge C rates and to keep the electrical contact between the host particles during repeated intercalation/deintercalation. This study has also emphasized that when high C-rate applications of lithium-ion batteries are targeted, it is important to get optimum content of MWCNT as well as uniform dispersion of their bundles in the composite anodes.