Fully Flexible Battery Could Revolutionize Smart Devices
Chinese scientists have developed a new fully flexible lithium-ion battery. This battery has the potential to revolutionize smart devices.
Chinese Scientists Develop Fully Flexible Lithium-Ion Battery
When it comes to batteries, flexible structures are usually the last thing that comes to mind. However, with the advancement of technology, the need for flexibility in this area is rapidly growing. Flexible batteries could bring significant changes in design and functionality to wearable smart and health devices, as well as smartphones. Now, Chinese scientists have taken a leap into the future by developing a new lithium-ion battery that is fully flexible in all its components.
Wide Range of Applications
Bending and stretching electronic devices require batteries with similar properties. Most researchers attempting to create such batteries have so far made them with rigid components folded into expandable shapes similar to origami. However, a truly flexible battery needs every part—including the electrodes and electrolyte layer—to be elastic. Until now, prototypes of genuinely flexible batteries have had moderate flexibility, complex assembly processes, or limited energy storage capacity, especially with repeated charging and discharging over time.
Researchers now report that they have developed a lithium-ion battery with fully flexible components, including an electrolyte layer that can stretch up to 5000%. Remarkably, the battery retains its capacity even after about 70 charge/discharge cycles. Unlike previous designs that relied on a weak connection between the electrolyte layer and the electrodes or used liquid electrolytes that could move when the battery changed shape, this new battery uses a fused polymer solid layer between two flexible electrode films. This design enhances the charge/discharge cycle, durability, and safety.
Ultimately, the solid flexible battery design developed by researchers demonstrated approximately six times higher average charging capacity in terms of fast charging compared to a similar device with a traditional liquid electrolyte. Additionally, the solid battery provided more stable capacity over 67 charge and discharge cycles. During the first 30 cycles, liquid electrolyte batteries typically experienced a 16% drop in electrolyte performance, whereas the solid polymer electrolyte showed only a 1% drop over the same number of cycles.
Steps Need to Be Taken
Steps Taken to Create Fully Flexible Battery
To make the electrodes for the fully flexible battery, the team spread a thin conductive paste film containing silver nanowires, carbon black, and lithium-based cathode or anode materials onto a plate. The researchers then added materials necessary to form a lithium salt, a highly conductive liquid, and a flexible polymer directly onto this film. When activated by light, these components combined to create a solid, rubbery layer that could stretch up to 5000% of its original length while carrying lithium ions. Finally, another electrode film was placed on top of the stack, and the entire device was coated with a protective layer.
Researchers acknowledge that the battery still has imperfections and requires many improvements. However, the successful implementation of the concept suggests that the final product may not be far off.
