Integrated Energy Conversion and Storage Systems

Integrated energy conversion and storage systems combine energy harvesting technologies with storage devices to create autonomous power units. By uniting photovoltaic, mechanical or thermal energy converters with batteries or supercapacitors in monolithic, flexible or wearable formats, these systems address the intermittency of renewable sources and the demand for compact, self-sustaining power. Key advances have been realised through novel architectures such as roll-to-roll textile hybrids, photo-rechargeable supercapacitors and quasi-solid-state electrolytes. Material innovations, including metal-organic frameworks, perovskites and two-dimensional semiconductors, have driven improvements in conversion efficiency, energy density and cycle life. These integrated platforms find applications in the Internet of Things, portable electronics and remote sensors, supporting a transition towards decentralised, carbon-neutral energy networks.

Research from Nature Portfolio

Recent studies have demonstrated photo-supercapacitors fabricated from nanoscaled ZnO in nanowire and nanoflower morphologies, achieving significant increases in coulombic efficiency and energy density under UV illumination while retaining near-perfect cycling stability. A foundational effort introduced roll-to-roll manufacture of cotton-textile hybrid solar-supercapacitor power packs, yielding flexible, self-sustaining energy ribbons capable of continuous electronic operation. Further work presented printed magnesium-ion quasi-solid-state asymmetric supercapacitors integrated with flexible solar cells, delivering over 17 % overall conversion-storage efficiency and excellent long-term mechanical robustness and cycling retention.

Integrated Energy Conversion and Storage Systems publication trend

The graph below shows the total number of articles in integrated energy conversion and storage systems across all publications each year (not limited to Nature Index journals).

Technical terms

Photocapacitor: Device integrating photovoltaic conversion and capacitive energy storage in one unit.

Supercapacitor: Energy storage device using electrostatic or pseudocapacitive charge accumulation for high power output.

Asymmetric supercapacitor: Supercapacitor employing different electrode materials to extend voltage range and improve energy density.

Quasi-solid-state electrolyte: Gel-like or polymeric medium offering ion conduction with enhanced mechanical and thermal stability.

Metal-organic framework (MOF): Porous crystalline assembly of metal ions and organic linkers used to increase electrode surface area and conductivity.

Perovskite solar cell: Photovoltaic device using a perovskite-structured light-absorbing layer to achieve high conversion efficiency.

References

1. Progress of Photocapacitors. Chemical Reviews (2023).
2. Photo‐Rechargeable Organic Supercapacitor via Light‐Activated Electrolytes. Advanced Science (2025).
3. Cotton-textile-enabled flexible self-sustaining power packs via roll-to-roll fabrication. Nature Communications (2016).
4. Printable magnesium ion quasi-solid-state asymmetric supercapacitors for flexible solar-charging integrated units. Nature Communications (2019).
5. Photo-supercapacitors based on nanoscaled ZnO. Scientific Reports (2022).
6. Photocatalysis‐Assisted Co3O4/g‐C3N4 p–n Junction All‐Solid‐State Supercapacitors: A Bridge between Energy Storage and Photocatalysis. Advanced Science (2020).
7. Recent Progress on Integrated Energy Conversion and Storage Systems. Advanced Science (2017).