Abstract
Concrete infrastructures face two major challenges: protecting embedded steel from corrosion and enabling multifunctional capabilities such as energy storage. Achieving durable reinforcement protection is essential for structural longevity, while integrating electrochemical functionality can transform concrete into an active component that supports low-carbon, smart infrastructure. Existing corrosion-mitigation methods and concrete batteries often compromise structural integrity or suffer from limited lifetime and low power output.
In this study, a discrete Zn-embedded cement-based anode (DZCA) and a Zn-anode rebar-reinforced cementitious battery (ZARCB) were developed to provide both cathodic protection and energy-storage capability. The DZCA acts as a sacrificial anode and the embedded rebar serves as the cathode, eliminating external electrodes and maintaining structural integrity. Performance was enhanced through increased electrolyte alkalinity, porosity optimization, biochar-induced pore regulation, and a PVA-hydrogel coating that improved ionic connectivity and interfacial stability.
Long-term durability was evaluated under simulated field stressors including chloride exposure and cyclic wet–dry conditions. High-alkalinity systems (>5 M KOH) provided superior corrosion protection, while the 5 M condition delivered the most stable microwatt-level energy output. Porosity optimization revealed a trade-off in which moderate porosity (9.1–11.6%) ensured stable long-term performance. Biochar addition buffered electrolyte fluctuations and sustained activity, and the hydrogel coating further enhanced stability and power delivery.
These results demonstrate that rational design of composition and microstructure can significantly improve the durability and multifunctionality of cement-based electrochemical systems. DZCAs offer a promising route toward self-sustaining, corrosion-resistant, and energy-integrated concrete infrastructures.