Stabilizing the Si/C blend anode by a multifunctional ternary composite binder.

• A CMC/CPAM/SBR ternary composite binder is proposed for Si-based anode. • Multifunctional groups are designed for matching the surfaces of both Si and carbon. • Regional elasticity and integral rigidness are achieved for the volumetric effects. • The cyclability of a Si@C/graphite blended anode is improved. • The binder is effective in high-loading electrodes and full cells. Si/C blend anodes hold great promise in commercialized high-energy-density (HED) Li-ion batteries but suffer from volumetric effects and electrode integrity deterioration. This study reports a ternary composite binder consisting of carboxymethyl cellulose (CMC), cationic polyacrylamide (CPAM), and styrene-butadiene rubber (SBR), which can significantly improve the cyclability of a Si@C/graphite blend anode. A high capacity retention of 92.9% after 100 cycles was achieved in a half cell. Moreover, the ternary binder proves suitable for a very high mass loading (4.9 mAh/g) electrode and is effective in a 2 Ah-level full cell, which delivers an excellent capacity retention of 80.6% after 500 cycles. The beneficial effects were ascribed to the multifunctional groups compatible with the surfaces of both Si and carbon, and the designed rigidness and elasticity which restricts and accommodates the volumetric effects of the Si/C blend anode simultaneously. [ABSTRACT FROM AUTHOR]