posted on 2021-01-29, 17:09authored byWei Wang, Yan Wang, Weibo Huang, Mi Zhou, Linze Lv, Ming Shen, Honghe Zheng
The
development of Si-based lithium-ion batteries is restricted
by the large volume expansion of Si materials and the unstable solid
electrolyte interface film. Herein, a novel Si capsule with in situ developed polymethyl methacrylate (PMMA) shell is
prepared via microemulsion polymerization, in which
PMMA has high lithium conductivity, high elasticity, certain viscosity
in electrolytes, as well as good electrolyte retention ability. Taking
advantage of the microcapsule structure with the PMMA capsid, the
novel Si capsule anode retains 1.2 mA h/cm2 at a current
density of 2 A/g after 200 electrochemical cycles and delivers higher
than 66% of its initial capacity at 42 A/g.