Entropy–Driven Dual–Channel Dissipative Binder for Strain–Responsive Reinforcement and Stable Silicon Anodes

Abstract

Dissipative smart binders hold great potential for flexible electronics and energy storage, but achieving synergistic regulation between energy dissipation and structural reinforcement remains challenging, particularly in balancing high strength, tunable toughness, and multifunctional integration. Here, a dissipative smart binder with a dual-channel responsive mechanism is developed to enable dynamic regulation of energy dissipation and rigidity enhancement through the synergistic effects of slip relaxation and conformational locking. Centered on Fe²⁺/Fe³⁺ dynamic coordination, the binder incorporates control via the intricate and rigid rosin architecture and a hierarchy of distinct bonding mechanisms, thereby enhancing its capacity for both rapid energy dissipation and strain-triggered reinforcement. Sodium alginate serves as a continuous phase framework, reinforced by phosphorylated cellulose nanocrystals, conformation-locking segments of acrylic acid rosin, and a multivalent coordination network that enables this strain-triggered state transformation. The binder exhibits a soft-to-rigid transition with a strain-rate-sensitive hardening effect, increasing modulus up to 98 000 times and fracture energy from 104.51 to 272.34 MJ m⁻³. Applied in silicon anodes, it maintains 2476.5 mA h g⁻¹ after 100 cycles at 0.2C, with ionic conductivity reaching 25.240 mS cm⁻¹, an eightfold increase over the unmodified system. The composite network effectively mitigates structural degradation, binder fatigue, and interfacial instability caused by silicon volume expansion.