Development of a stretchable and printable free-form lithium-ion battery

A Korean research team has developed a soft, mechanically deformable, and expandable lithium battery that can be used in the development of wearable devices, and investigated the battery’s feasibility by printing them on clothing surfaces. of the Soft Hybrid Materials Research Center at the Korea Institute of Science and Technology (KIST; President: Seok-Jin Yoon). The research team, led by Jeong Gon Son, announced that they have developed a lithium battery in which all materials, including anode, cathode, current collector, electrolytes and encapsulant, are stretchable and printable. The lithium battery developed by the team has high capacity and free-form characteristics suitable for mechanical deformation.

Due to the rapidly increasing demand for high-performance wearable devices – such as smart bands, implantable electronic devices such as pace-makers, and soft wearable devices for use in realistic metaverses – the development of a battery that is soft and stretchable . Human skin and organs are attracting interest.

The rigid, inorganic electrodes of a conventional battery make up most of the battery’s volume, making it difficult to pull. Other components, such as the separator and the current collector, for drawing and transferring charge, must also be stretchable, and the problem of liquid electrolyte leakage should also be solved.

To increase stretch, the research team avoided using materials used in other studies that were unnecessary for energy storage, such as rubber. Then, a new soft and stretchable organic gel material was developed and applied based on the existing binder material. This material holds the active electrode material firmly in place and facilitates the transfer of ions. In addition, a conductive ink was created using a material with excellent stretch and gas barrier properties to serve as a current collector material that transfers electrons and an encapsulant that causes swelling at high voltages and in various deformed states. Can work stably without Electrolyte absorption.

The battery developed by the team is also able to incorporate existing lithium-ion battery materials, as they exhibit excellent energy storage density (~2.8 mWh/cm)²) of the same level as a commercially available hard lithium-ion battery at a driving voltage of 3.3 V or higher. All constituent components of the team’s stretchable lithium-ion battery have mechanical stability that allows the battery to maintain its performance even after repeated stretching of 1,000 or more times, high stretchability of 50% or more, and long-term stability in air. is for.

In addition, the research team directly printed the electrode and current collector material they had developed on either side of an arm warmer made of spandex and applied a stretchable encapsulant to the material, which directly printed a stretchable high-voltage organic battery. Demonstrates ability to. Clothes. Using the resulting battery, the research team was able to keep a smart watch running continuously, whether it was being powered on, taken off, or extended.

Dr. Son at KIST said his team has developed a stretchable lithium-ion battery technology that provides both structural freedom as a result of the free-form configuration of the battery, allowing it to be printed on materials such as fabric, and material independence. Permission is granted. In addition to the stretch stability being able to use existing lithium-ion battery materials that allow for higher energy density and mechanical deformation. He also said that the stretchable energy storage system developed by his team is expected to be applied to the development of various wearable or body-attached devices.

The research results were published in ACS Nano,

Provided by National Council of Science and Technology Research