Flexible Supercapacitor Technologies for Energy Storage Applications

Flexible supercapacitors have emerged as key components in next-generation energy storage systems, combining rapid charge–discharge capability, long cycle life and mechanical resilience in deformable formats. Unlike conventional rigid capacitors and batteries, these devices can accommodate bending, stretching and folding without significant loss of performance, making them ideal for wearable electronics, soft robotics and implantable sensors. Progress has been driven by advances in electrode materials (carbon fibres, graphene, metal oxides, two-dimensional materials), gel and solid-state electrolytes, and novel device architectures such as fibre assemblies, paper-based films, textile integrations and kirigami-inspired layouts. Central challenges remain the simultaneous optimisation of energy density, power density and mechanical durability, along with scalable, low-cost fabrication. Recent work spans microfluidic fabrication of hybrid fibres, bottom-up gel infilling of thick electrodes for high areal capacitance, and sustainable substrate approaches for textile integration. These developments point towards truly conformable energy storage solutions that can be seamlessly embedded into everyday objects and advanced electronic systems.

Research from Nature Portfolio

Recent studies have demonstrated hetero-structured electrode designs and advanced assembly techniques to boost both energy density and flexibility. One investigation employed a microfluidic-spinning process to produce black phosphorus–carbon nanotube hybrid microfibres, which were assembled into non-woven fabrics. The resulting electrodes exhibited volumetric capacitance exceeding 300 F cm⁻³, energy density near 100 mW h cm⁻³ and excellent cycle stability under repeated deformation. Another report introduced a bottom-up infilling method for thick porous electrodes composed of carbon nanotubes and conducting polymers, enabling gel electrolytes to penetrate 500 µm-thick films without voids. These solid-state devices retained over 95% capacitance after thousands of bending cycles and achieved areal capacitances above 2600 mF cm⁻². More recently, a sustainable textile approach used bamboo fabric as a substrate for printed metal-oxide and reduced graphene oxide electrodes with a gel electrolyte, producing an asymmetric battery–supercapacitor hybrid. This device delivered areal capacitance over 2 F cm⁻², energy densities above 35 mW h cm⁻³ and maintained performance under bending and stretching, illustrating the promise of eco-friendly, wearable power sources.

Flexible Supercapacitor Technologies for Energy Storage Applications publication trend

The graph below shows the total number of articles in flexible supercapacitor technologies for energy storage applications across all publications each year (not limited to Nature Index journals).

Technical terms

Electric double-layer capacitance (EDLC): Charge storage mechanism at the electrode–electrolyte interface, using electrostatic separation of ions without faradaic reactions.

Pseudocapacitance: Charge storage via fast surface or near-surface redox reactions, contributing additional capacitance beyond EDLC.

Areal capacitance: Capacitance normalised by electrode surface area (F cm⁻²), indicating how much charge can be stored per unit footprint.

Gel electrolyte: A semi-solid ion-conducting medium that combines mechanical stability with ionic transport, reducing leakage risk compared with liquid electrolytes.

Microfluidic spinning: Technique for continuous production of microfibres by controlling precursor flows in microchannels, enabling aligned architectures and compositional heterostructures.

Kirigami patterning: Laser or mechanical cutting strategy that introduces slits into flat materials, permitting controlled multi-directional stretching and bending.

MXene: Family of two-dimensional transition metal carbides or nitrides with high conductivity and surface functionality, used as electrode materials.

References

1. Microfluidic-spinning construction of black-phosphorus-hybrid microfibres for non-woven fabrics toward a high energy density flexible supercapacitor. Nature Communications (2018).
2. High energy flexible supercapacitors formed via bottom-up infilling of gel electrolytes into thick porous electrodes. Nature Communications (2018).
3. Configuration‐dependent stretchable all‐solid‐state supercapacitors and hybrid supercapacitors. Carbon Energy (2023).
4. Smart Electronic Textile‐Based Wearable Supercapacitors. Advanced Science (2022).
5. Kirigami Patterning of MXene/Bacterial Cellulose Composite Paper for All‐Solid‐State Stretchable Micro‐Supercapacitor Arrays. Advanced Science (2019).