Flexible Lithium-Ion Battery Technologies

Flexible lithium-ion batteries (LIBs) are emerging as key enablers for next-generation wearable electronics, soft robotics and rollable displays. Unlike conventional rigid cells, flexible LIBs integrate pliable electrodes, bendable separators and compliant current collectors to maintain electrochemical performance under repeated deformation. Central to this field are self-supporting or binder-free electrode architectures that replace metal foils with three-dimensional conductive networks. These networks—often based on carbon nanotubes, graphene or carbon fibres—offer both electron transport pathways and mechanical resilience. Recent advances have focused on enhancing rate capability and cycle life through engineered interfaces, novel electrode formulations and scalable fabrication methods. The global drive towards lightweight, compact and durable energy storage has spurred interdisciplinary research into materials chemistry, device engineering and manufacturing processes. Practical demonstrations range from foldable battery modules for smart textiles to stretchable cells for biomedical sensors, underscoring the broad significance of flexible LIB technologies.

Research from Nature Portfolio

A foundational study introduced a nitrogen-doped carbon paper as a free-standing anode, produced by compressive pyrolysis of melamine foam. The resulting three-dimensional cellular network exhibits excellent bending flexibility and obviates binders, conductive additives and metal current collectors. As anodes in lithium-ion cells, these carbon papers deliver over 300 mAh g⁻¹ after extended cycling at moderate rates and retain significant capacity at high current densities. The work underscores the role of dense junctions between carbon strands in facilitating rapid electron transfer and short lithium-ion pathways, and it established a benchmark for flexible, binder-free electrode design.

Flexible Lithium-Ion Battery Technologies publication trend

The graph below shows the total number of articles in flexible lithium-ion battery technologies across all publications each year (not limited to Nature Index journals).

Technical terms

Binder-free electrode: A self-supporting electrode architecture that does not require polymeric binders to hold active materials, relying instead on conductive networks for both mechanical integrity and electron transport.

Self-supporting electrode: An electrode capable of maintaining its shape and mechanical stability without rigid substrates or metal foils, often achieved using three-dimensional conductive frameworks.

Current collector: A conductive layer that gathers electrons from the electrode material; in flexible LIBs it is frequently replaced by carbon fabrics or nanotube films instead of metal foil.

Specific capacity: The amount of electric charge stored per unit mass of active material, typically expressed in milliampere-hours per gram (mAh g⁻¹).

Rate capability: The ability of a battery to charge and discharge at high current densities while retaining capacity, indicating fast ion and electron transport.

Interfacial adhesion: The chemical and mechanical bonding at the junction between electrode layers or between electrode and separator, critical for maintaining performance under deformation.

References

1. Nitrogen-doped carbon paper with 3D porous structure as a flexible free-standing anode for lithium-ion batteries. Scientific Reports (2017).
2. Preparation of Tough, Binder‐Free, and Self‐Supporting LiFePO4 Cathode by Using Mono‐Dispersed Ultra‐Long Single‐Walled Carbon Nanotubes for High‐Rate Performance Li‐Ion Battery. Advanced Science (2023).
3. Ultrastable Interfacial Contacts Enabling Unimpeded Charge Transfer and Ion Diffusion in Flexible Lithium‐Ion Batteries. Advanced Science (2022).