Abstract:

Concrete-based energy storage batteries embed electrochemical energy storage units into cement-based materials， enabling structural components to have electrical energy storage function in addition to their load-bearing role. It offers a novel material solution for building energy saving， renewable energy consumption， and infrastructure energization. Recent studies on concrete-based supercapacitors and concrete-based secondary batteries are summarized， covering material composition， structural configuration， performance evaluation， and application progress. The focus is placed on the coordination between energy storage performance and structural performance. Existing studies mainly focus on electrodes， electrolytes， separators， current collectors， and component structures. For electrodes， carbon black， carbon fibers， carbon nanotubes， and graphene can form conductive networks in cement matrices and are suitable for constructing electric double-layer capacitance systems. Metal oxides， metal hydroxides， metal nitrides， and conductive polymers can provide pseudocapacitive or battery-type reactions， contributing to increased capacity. However， their interfacial stability in alkaline pore solution and humid environments remains a challenge that needs to be addressed. In terms of fabrication， in-situ compounding facilitates integration with the concrete casting process. Electrochemical deposition can improve electrode surface activity. Template-assisted methods are beneficial for forming porous transport channels， and 3D printing enables the directional arrangement of electrodes and load-bearing regions. For electrolytes， liquid electrolytes have high ionic conductivity but are prone to leakage. Solid cement-based electrolytes provide better safety and load-bearing capacity but have insufficient transport efficiency. Gel electrolytes show relatively balanced performance in water retention， leakage resistance， and interfacial wetting. Separator materials also evolve from ordinary porous membranes toward cement-based and polymer-cement composite separators to simultaneously meet the requirements of electrode isolation， ion transport， and mechanical support. Related studies have been preliminarily validated in scenarios such as wall-integrated energy storage， LED power supply， pavement wireless charging， and structural health monitoring. However， most of the existing results remain at the stage of small-sized specimens or laboratory-scale devices. The key limitations of concrete-based energy storage batteries are as follows. Conductive phases and pore structures are beneficial for electrochemical performance but may compromise matrix compactness and mechanical strength. The durability of metal components in highly alkaline and moist environments remains insufficient. The energy density， cycling stability， and engineering-scale consistency of the devices are still insufficient to meet long-term service requirements. Future research should focus on alkali-resistant conductive frameworks， polymer-cement composite electrolytes， functional aggregates derived from industrial solid waste， gradient pore design， and directional forming by 3D printing. Long-term testing methods for service environments should also be established. By rationally distinguishing energy storage functional zones from load-bearing functional zones， the engineering applicability of such materials in building components and intelligent infrastructure can be gradually enhanced.

Key words: concrete-based batteries, capacitors, electrodes, electrolytes, separators, wall-integrated energy storage