From Electrodes to Devices: Reimagining Aqueous Supercapacitors, Supercapatteries, and Rechargeable Batteries for Safe and Sustainable Energy Storage

Water-based electrochemical energy storage is rapidly emerging as a key enabler in the pursuit of safe, sustainable, and cost-effective energy solutions. Characterized by high ionic conductivity, environmental compatibility, and intrinsic fire safety, aqueous systems offer a compelling alternative to organic and solid-state counterparts. However, their relatively narrow electrochemical stability window continues to restrict voltage and energy density. Recent progress has seen a convergence between aqueous supercapacitors, supercapatteries, and rechargeable batteries, where capacitive and faradaic chemistries merge to deliver improved performance. Innovations in zinc-ion, aqueous sodium-/potassium-ion, and proton batteries, alongside hybrid and high-concentration electrolyte strategies, are redefining possibilities for high-energy yet safe electrochemical devices. Despite these advances, a systematic understanding linking molecular-scale design to device-level metrics remains underdeveloped. This gap underscores the urgent need for coordinated efforts that integrate materials innovation, interface engineering, and practical performance evaluation.

This Research Topic aims to drive the development of aqueous electrochemical energy storage systems by uniting breakthroughs across electrode architectures, electrolyte formulations, and device designs. The goal is to establish design principles that deliver energy densities approaching or surpassing lead–acid benchmarks while maintaining the cost efficiency, durability, and sustainability that make aqueous systems strategically attractive. A particular focus lies in understanding how electrode composition, nanostructure, and electrolyte chemistry can be co-optimized for extended voltage windows, stable cycling, and scalable manufacturing. By connecting materials chemistry to real-world performance, this initiative seeks to accelerate the transition of aqueous energy storage from laboratory concepts to practical technologies suitable for grid balancing, mobility applications, and wearable electronics.

To gather further insights into aqueous-based electrochemical systems across performance scales, we welcome articles addressing, but not limited to, the following themes:
- Electrode materials: carbon-based, metal oxide/hydroxide, conducting polymer, MXene, hybrid composites, and high-entropy or defect-engineered structures
- Electrolyte engineering: neutral, acidic, alkaline, and “water-in-salt” electrolytes; gel, semi-solid, and quasi-solid systems; additives for voltage-window extension
- Electrode/electrolyte interface phenomena: charge-transfer and storage mechanisms, SEI/CEI analogues in aqueous media, corrosion and dendrite suppression
- Aqueous rechargeable batteries: zinc-ion, sodium-/potassium-ion, proton, and flow chemistries; design strategies for anode protection and long cycle life
- Device design and architectures: symmetric/asymmetric supercapacitors, supercapatteries, and full-cell battery systems with broadened operating voltages
- Flexible and wearable aqueous devices: printable, robust, and biocompatible systems optimized for portable applications
- Performance benchmarking: full-cell data, practical testing conditions, rate and temperature effects, and long-term durability
- Sustainability and real-world impact: techno-economic analysis, recyclability, life-cycle assessment, and deployment for grid, transport, and wearable sectors.

Article types and fees

This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:

• Editorial
• FAIR² Data
• Mini Review
• Original Research
• Perspective
• Review

Articles that are accepted for publication by our external editors following rigorous peer review incur a publishing fee charged to Authors, institutions, or funders.

Article types

This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:

• Editorial
• FAIR² Data
• Mini Review
• Original Research
• Perspective
• Review

Keywords: Aqueous electrolytes, Supercapatteries, Electrode-electrolyte interface, Sustainable energy storage, Rechargeable batteries

Important note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.