A new universal aqueous conductive binder via esterification reinforced electrostatic/H-bonded self-assembly for high areal capacity and stable lithium-ion batteries

Abstract

Because of insufficient adhesivity and mechanical properties, conventional polymeric binders fail to accommodate immense volume changes and maintain interparticle connections upon the repeated charge/discharge processes, especially in high active material loading and thick electrodes. Here, a new water-soluble conductive binder (APA/CNT) composed of carboxylic carbon nanotubes interwoven in flexible membranes of the neutralising product of 6-amino-1-hexanol and commercial poly(acrylic acid) (PAA) is developed. The APA/CNT is expected to form robust conductive and elastic network by means of the esterification reinforced electrostatic/H-bonded self-assembly, in which the continuous conductive skeletons can segregate and grasp active nanoparticles by an efficient and robust “sheet-to-point” bonding mode, which endows the as-fabricated anode and cathode with extraordinary structural and interfacial stability, and enhanced electronic conductivity. The as-constructed Si/C anode exhibits superior cycling stability and a high rate performance even under a high mass loading of 15 mg cm⁻², and achieves a high areal capacity of 7.79 mA h cm⁻², far exceeding those of other binder-based Si/C anodes. Moreover, the as-fabricated full cell also displays enhanced electrochemical behaviour and cycling durability. This simple and easy strategy should give a valuable new way to design a cost-effective, universal yet environmentally friendly binder with dependable adhesiveness for high-performance devices.