Researchers at the Massachusetts Institute of Technology (MIT) have recently developed a rechargeable lithium-ion battery that is very long and can be woven into yarn like fabric. This battery can power a wide range of wearable electronic devices and may even be used to make 3D printing batteries in almost any shape.
These researchers have created new perspectives on the construction of electronic devices that provide the energy they need; Devices with the use of communication and sensors and calculations that are wearable like ordinary clothes. Also, in cases where the battery is powered by an additional power supply, it can act as part of the body of the electronic device.
The technology team has produced the world’s longest flexible, 140-meter-long fiber-optic battery to show that it can be built to any length. The results of this study are presented in detail in the journal Materials Today. Earlier, researchers had introduced a variety of flexible electronic components; Including light emitting diodes (LEDs), sensors and optical detectors and communication and digital systems.
The ability to weave and wash these devices has made them practical tools in wearable products; But so far they have all relied on external energy sources. Now, this fiber battery can completely eliminate the need for such devices from external power supplies. This technology is made using energy-saving gels and a standard fiber production system.
The process of making the battery starts from heating a large cylinder that contains all the components of the battery, to near its melting point. This material becomes doughy due to heat and is pulled from a narrow opening to the point that its thickness is greatly reduced while maintaining the arrangement of its main parts. Tural Khodif“One of the researchers at MIT and current assistant professor at the National University of Singapore (NUS) says:
Many research teams have tried to make fiber batteries; But the basic material of their batteries is outside the fiber. The interesting thing about this battery is that it contains lithium and other materials inside the fiber. Also, the outer protective cover is installed so that the battery is stable and waterproof. This is the first practical fiber battery that is long enough and durable enough. The sensitive components of the battery are sealed before being embedded in the fiber, and all active ingredients are reliably integrated; Therefore, their position does not change during the manufacturing process.
By introducing a 140-meter fiber battery, this research group has actually shown that there is no limit to the length of this battery. “We can definitely build a long, flexible battery on a kilometer scale,” Khodyev said. To demonstrate battery performance, it was used in a Li-Fi-based communication system including a microphone, amplifier, transistor and diode to transmit optical data between two wearable electronic devices.
The built-in fiber battery is much thinner and more flexible than similar types, with a length-to-width ratio of up to one million. These features allow the battery to be woven into wearable tools with standard knitting equipment. The 140-meter battery, which is only a few hundred microns thick, has a 123 mAh energy storage capacity that can charge a smartwatch or cell phone. Jung Tae Lee, Another researcher of this project says:
A special feature of our approach is that, unlike others, which require the integration of multiple fiber devices, we can embed multiple devices in a single fiber.
Lee believes that in the future more than three or four devices can be placed in such a small space. This, if realized, would lead to fabric and wearable computer technology.
In addition to the one-dimensional fibers that can be used to produce fabric, this battery can also be used in three-dimensional printing. To demonstrate this capability, a toy submarine was built in which the battery was wrapped around the body of the device to power it. The inclusion of a power supply in the structure of such devices can reduce the overall weight and thus improve their efficiency and operating radius. “You know,” he said.
This is the first 3D printing of a device with a fiber battery. No need to add anything after printing; Because all metals and active ingredients are inside the fiber. This means that processors, such as Li-Fi, can now be housed inside everyday objects. In the next few years, fiber batteries will be available in commercial products.