Water-soluble silicon anode binder containing polyacrylic acid with an integrated diarylbibenzofuranone cross-linked structure, a silicon anode containing the same, and a lithium secondary battery containing the anode.

Water-soluble silicon anode binder based on a reversible C-C bond self-healing cross-linked network

This technology utilizes the self-healing properties of diarylbibenzofuranone (DABBF) through reversible carbon-carbon (C-C) bond formation and cleavage to create a 3D cross-linked network between polyacrylic acid (PAA) polymer chains, effectively suppressing the repetitive volume expansion of silicon anodes and maintaining electrode structural integrity.

Silicon anodes suffer from rapid capacity degradation due to excessive volume expansion of up to 400% during charge and discharge cycles, which causes internal electrode cracking, loss of electrical contact between active materials and conductive agents, and excessive SEI layer formation that increases resistance.

This technology forms a 3D cross-linked network by esterifying PAA with a DABBF cross-linker synthesized from a 3-hydroxypropoxy arylbenzofuranone (PABF) precursor, maximizing mechanical properties and adhesion at a composition of 1–5 wt% (recommended 2.5 wt%). It can be applied to high-capacity silicon-rich anodes or water-based electrode slurry production lines, where self-healing bonds repair expansion-induced fractures and delay the accumulation of electrode cracks.

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Key Features:

• Water-soluble silicon anode binder containing polyacrylic acid (PAA) with an integrated diarylbibenzofuranone (DABBF) cross-linked structure
• Diarylbibenzofuranone cross-linker included at a content of 1 wt% to less than 5 wt% relative to 100 wt% of polyacrylic acid
• Step of synthesizing a diarylbibenzofuranone (DABBF) precursor compound from 3-hydroxypropoxy arylbenzofuranone (PABF) for binder production
• Step of reacting polyacrylic acid (PAA) with the DABBF precursor compound to synthesize a 3D cross-linked network structure of polyacrylic acid

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