A novel organosilicon-type binder for LiCoO₂ cathode in Li-ion batteries

The conventional binder used in LIBs, polyvinylidene fluoride (PVDF), possesses low mechanical ductility and weak affinity to electrode materials and therefore cannot prevent pulverization of the cathode materials or undesirable battery swelling after prolonged cycling. Herein, we introduce a novel organosilicon-type binder (S-binder), composed of siloxane (Si–O–Si), silanol (Si–O–H), and cyclohexene oxide (C₆H₁₀O) groups. It is demonstrated that S-binder exhibits the enhanced adhesion to the cathode, high elasticity, and great flexibility compared with PVDF, resulting in exceptionally improved electrochemical performances of LiCoO₂. In terms of cyclability, S-binder-applied LiCoO₂ electrode with high mass loading of the active material (∼8 mg cm⁻²) exhibits outstanding capacity retention of ∼92.0% compared with the initial capacity after 100 cycles. From industrial perspective, simulation of the slot-die coating on S-binder- and PVDF-applied slurries indicates the high competitiveness of S-binder compared with PVDF for the mass-production of LiCoO₂ electrode for LIBs.