A Korean research team has developed a new type of lithium-ion battery. It brings with it exciting properties and can, among other things, vigorously promote the topic of wearables. The first practical test was very promising.
The further development of the digital world depends on the power supply, more precisely on batteries. When they hear the term "batteries", many people still think of small, solid rolls that are pushed into the corresponding plastic compartments of electronic devices. Engineers, on the other hand, know that there have long been handy energy storage devices in shapes and sizes that were previously unimaginable. Nevertheless, the existing lithium-ion batteries are far from being able to meet all the desired applications.
A good example is smart clothing. On the one hand, it is interesting for athletes in the leisure sector, on the other hand, it could develop great potential in the field of medicine. T-shirts that record the heart rate or even the blood sugar levels of the wearer via integrated sensors would enable doctors to tailor therapies more precisely to the patient and to dose medication better. The smart clothing could even pass on behavioral tips, for example to regulate a heart rate that is too high. It could also collect important data for diagnostics. It's all possible, at least in theory. In practice, it is often the inadequate energy supply that means that interesting pilot projects do not reach the masses. This could change now. Because scientists from Korea have presented a new type of lithium-ion battery. Its properties surprise.
Lithium-ion battery is mechanically very flexible
The research team led by Dr. Jeong Gon Son of the Korea Institute of Science and Technology (KIST) Soft Hybrid Materials Research Center has developed a lithium-ion battery in which all materials used are stretchable and can be printed on clothing. The main reason why the new battery is portable is its mechanical flexibility - it can be easily stretched and, according to the researchers, feels comfortable.
This would eliminate a major disadvantage of conventional batteries: their hard, inorganic electrodes. It normally takes up most of the battery volume. Extensibility is not usually one of their properties. Another difficulty is the liquid electrolytes, which must not leak.
Conductive ink allows for electron transfer
The goal was clear to the scientists. That's why they ruled out from the outset materials that are stretchable but don't store any energy, such as rubber. Instead, they developed a new organic gel material. It is soft, stretchy and created from the existing binding material. It holds the active electrode materials in place and facilitates the transfer of ions. In the next step, the researchers produced a kind of conductive ink. It serves as a current collector material for electron transfer. It also forms an encapsulation so that the battery can function stably even at high voltage and in various states of deformation without swelling due to electrolyte absorption.
Rubber batteries give amazing results
According to the Koreans, the energy storage density should be comparable to the values of conventional lithium-ion batteries (~2.8 mWh/cm2), with a drive voltage of 3.3 volts or higher. It is therefore even possible to integrate materials into the battery that are used for conventional lithium-ion batteries.
Stretchable lithium-ion battery passes the practical test
The practical test has shown that the battery is mechanically very stable and its performance should remain the same even if it has been stretched 1,000 times.