Marking a stark departure from most people’s impression of li-ion batteries, a team from MIT recently developed a type of li-ion battery sporting a unique look. Despite being only a few hundred micrometers in thickness, said battery can be as long as 140 m and even 1 km potentially. In the future, there is a chance that these batteries can be integrated into normal clothing and become a clandestine fabric, of sorts, that silently charges smart clothes and wearables.
Such battery can not only serve as a power source, but also double as part of clothing fabric. In reality, researches from as early as 2014 echoed this sentiment. For instance, China’s Fudan University created a li-ion battery using carbon nanotubes. Additionally, Binghamton University arrived at a battery solution composed of highly stretchable, fabric-based, sweat-powered battery in 2017.
According to MIT’s press release:
The new fiber battery is manufactured using novel battery gels and a standard fiber-drawing system that starts with a larger cylinder containing all the components and then heats it to just below its melting point. The material is drawn through a narrow opening to compress all the parts to a fraction of their original diameter, while maintaining all the original arrangement of parts.
The team also indicates that what makes the battery special is that key components such as lithium form a structure inside the fiber, a structure that is protected on the outside by a coating. On the other hand, the new gel diodes and gel electrolytes also make the battery more fire resistant.
▲ The new fiber batteries on the right are more fire-resistant.
One cannot help but recall that the MIT team was also able to successfully embed digital chips into battery fibers. Research author Tural Khydiyev indicates that, once active materials are successfully embedded into said fibers, the fragile battery components are in turn sealed, not to mention the fact that most active materials are arranged in an orderly fashion without being easily shifted position-wise.
Ultimately, the team was able to create a thinner, more agile flexible fiber battery which, at 140 m long, is the longest in the world, albeit at a capacity of merely 123 mAh. However, the team indicates that the batteries will “grow up” in the future, with Khudiyev pointing out that there is no limit to the theoretical length of MIT’s fiber battery, meaning a 1 km length is definitely within the realm of possibility.
The new fiber battery is also machine washable. The team believes that such a property means these batteries can eventually be used as either a underwater source of electricity or a power supply for smartwatches and smartphones. As part of the demonstration equipment, the MIT team also integrated said batteries into Li-Fi systems, which use LED as signal transmitters. Embedded in the fibers are microphones, preamps, transistors, and diodes – all of which enables the establishment of optical data links between batteries.
▲ The supply of electricity continues despite the cut wire.
Jung Tae Lee, the author of the research, believes that embedding multiple sets of equipment into a single fiber enables the gradual creation of compact fabric computers. Although MIT has currently applied for patents, the research team is still hard to work optimizing their research with respect to battery efficiency and capacity in hopes that commercialization can be reached within the next few years.