Carbon black and alkali-activated slag composites for structural supercapacitors
Jiaxi Cheng, Gonghui Gu, Mengkang Zheng, Chuanqing Fu, Hailong Ye
Abstract
To tackle the challenges of intermittency and instability of clean energy sources and high manufacturing costs of conventional storage materials, this study develops cost-effective structural supercapacitors (SSCs) by combining carbon black (CB) and alkali-activated slag (AAS), as an affordable and scalable energy storage solution. Two CB dispersion methods—Method A (dry mixing followed by wet mixing) and Method B (ultrasonic dispersion followed by wet mixing)—are systematically compared regarding their impact on the microstructure and energy storage performance of the innovative CB-AAS composites through mechanical, structural, and electrochemical characterizations. Results indicate that Method B significantly improves CB dispersion and ion conductivity, leading to greater hardness (HV=3.9) and higher coulombic efficiency (79 %), while Method A achieves higher specific capacitance (95 mF/cm 2 ) at high CB content but suffers from reduced efficiency and structural deformation due to excessive mesopores. This study provides theoretical insights and technical guidance for the development of low-cost, high-performance energy storage building materials, advancing the integration of structure and functionality in buildings and infrastructure. • Low-cost CB-AAS SSCs enable energy storage in building materials. • Dispersion methods impact CB-AAS microstructure and electrochemical properties. • Macropores boost Coulombic efficiency, and mesopores enhance specific capacitance.