Carbon Microstructure Dependent Li-Ion Storage Behaviors in SiOx/C Anodes

SiOx anode has a more durable cycle life than Si, being considered competitive to replace the conventional graphite. SiOx usually serves as composites with carbon to achieve more extended cycle life. However, the carbon microstructure dependent Li-ion storage behaviors in SiOx/C anode have received insufficient attention. Herein, this work demonstrates that the disorder of carbon can determine the ratio of inter- and intragranular Li-ion diffusions. The resulted variation of platform characteristics will result in different compatibility when matching SiOx. Rational disorder induced intergranular diffusion can benefit phase transition of SiOx/C, benefiting the electrochemical performance. Through a series of quantitative calculations and in situ X-ray diffraction characterizations, this work proposes the rational strategy for the future optimization, thus achieving preferable performance of SiOx/C anode.

Automated summary

SiOx anode has a more durable cycle life than Si and can replace conventional graphite. However, the influence of carbon microstructure on Li-ion storage behavior in SiOx/C anode has been insufficiently considered. This study shows that the disorder of carbon can determine the ratio of inter- and intragranular Li-ion diffusions. Rational disorder-induced intergranular diffusion can benefit the phase transition of SiOx/C and improve its electrochemical performance.