Dual-confined SiOx encapsulated in PVA derived carbon layer and chitin derived N-doped carbon nanosheets for high-performance lithium storage

SiOx anodes hold great promise for next-generation lithium-ion batteries (LIBs) due to the high capacity and enhanced cycling stability versus silicon. However, its long-term development is hampered by seeking a scalable and effective method to tackle the issues of low conductivity and large volume expansion. Herein, a novel anode material is constructed by wrapping SiOx into PVA derived carbon layer and N-doped carbon (NC) nanosheets derived from exfoliated chitin nanosheets. The SiOx nanoparticles tightly encapsulated by the chitin nanosheets and PVA are transformed to robust SiOx@NC composites after pyrolysis. The encapsulation of PVA derived carbon layer and the NC sheets enhances the conductivity, relieves the volume change, and contributes to forming a stable SEI film. As a result, the prepared SiOx@NC-2 anode delivers a stable cycling performance and competitive rate capability. After 300 cycles at 0.5 A g-1, a relatively high capacity of 602 mA h g-1 is maintained. The cost-effective precursors and facile synthetic route can promote the application of the SiOx@NC composites as anode materials in energy storage, as well as facilitating the large-scale application of the biowaste derived chitin.

Automated summary

A novel anode material is constructed by wrapping SiOx nanoparticles into PVA derived carbon layer and NC nanosheets, addressing issues of low conductivity and volume expansion, resulting in stable cycling performance and competitive rate capability.