An All-Integrated Anode via Interlinked Chemical Bonding between Double-Shelled–Yolk-Structured Silicon and Binder for Lithium-Ion Batteries

Abstract

The concept of an all-integrated design with multifunctionalization is widely employed in optoelectronic devices, sensors, resonator systems, and microfluidic devices, resulting in benefits for many ongoing research projects. Here, maintaining structural/electrode stability against large volume change by means of an all-integrated design is realized for silicon anodes. An all-integrated silicon anode is achieved via multicomponent interlinking among carbon@void@silica@silicon (CVSS) nanospheres and cross-linked carboxymethyl cellulose and citric acid polymer binder (c-CMC-CA). Due to the additional protection from the silica layer, CVSS is superior to the carbon@void@silicon (CVS) electrode in terms of long-term cyclability. The as-prepared all-integrated CVSS electrode exhibits high mechanical strength, which can be ascribed to the high adhesivity and ductility of c-CMC-CA binder and the strong binding energy between CVSS and c-CMC-CA, as calculated based on density functional theory (DFT). This electrode exhibits a high reversible capacity of 1640 mA h g⁻¹ after 100 cycles at a current density of 1 A g⁻¹, high rate performance, and long-term cycling stability with 84.6% capacity retention after 1000 cycles at 5 A g⁻¹.

An all-integrated anode design via multicomponent chemical interlinking among carbon@void@silica@silicon (CVSS) nanospheres and cross-linked carboxymethyl cellulose and citric acid polymer binder (c-CMC-CA) is developed for achieving electrode/structural stability of a silicon anode during lithiation/delithiation. The obtained excellent electrochemical performance can be ascribed to the collaboration of the double-shelled–yolk-structured silicon and the covalent-interlinked high-strength binder system.

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