A biomass hydrogel electrolyte with a 3D dynamic interpenetrating network structure exhibting enhanced self-healing and electrochemical performances

Abstract

A self-healing hydrogel electrolyte was fabricated by integrating CNTs-COOH as a three-dimensional conductive scaffold, demonstrating synergistic properties of enhanced electrochemical performance and biodegradability. This well-designed strategy for introducing CNTs-COOH can not only improve the mechanical properties and self-healing performance of the hydrogel electrolyte, but also booste its electrical conductivity. The results showed that when CNTs-COOH content was 0.1 wt%, the tensile strength of the CPZC-0.1C gel reached 63.93 kPa, up from 17.78 kPa, while the stress self-healing efficiency achieved 98.49%. More critically, the battery assembled with CPZC-0.1C delivered an ionic conductivity of 2.63 × 10⁻³ S cm⁻¹, retained ∼73% of its initial capacity after 2000 cycles at 2 A g⁻¹, with a Coulombic efficiency close to 91%, exhibited satisfactory long-term cycling stability, good rate capability and excellent Coulomb efficiency. Even after three cut/self-healing events within 200 cycles, the battery still maintained ∼60% of its capacity, evidencing outstanding multi-cycle self-healing stability. The electrochemical performance of the healed battery is virtually identical to that of the pristine battery. Moreover, CPZC-0.1C gel electrolytes are environmentally safe and ambietly degradable, making them sustainable candidates for eco-friendly batteries with promising application prospects.