New Material: New Flexible Fiber Energy Storage Equipment Can Be Worn On The Body

Flexible fiber battery is a very interesting battery. Peng Huisheng's team of Fudan University first proposed and realized fiber lithium-ion battery in the world in 2013. The battery is a flexible one-dimensional fiber, which can be woven into various flexible textiles. Fiber is very common in daily life (for example, the clothes we wear and the carpets we walk on are woven from fiber). Imagine that if energy storage capacity is combined into fiber and then woven into usable textiles, it will bring about earth shaking changes in our life. At that time, batteries can be worn like clothes, providing power for countless electronic devices, A mobile power bank is formed.

Who is Peng Huisheng, who took the lead in realizing fiber lithium-ion battery? According to the public data, he is the winner of the National Science Fund for Distinguished Young Scholars, the national young and middle-aged expert with outstanding contributions, and the chief scientist of the national key research and development program. In October 2006, he joined the Los Alamos National Laboratory of the U.S. Department of Energy and began to engage in research independently, In October 2008, he returned to work in Fudan University and is now a professor and doctoral supervisor of the Department of Polymer Science and Advanced Materials Laboratory.

As early as September 2021, his team published a paper in the top academic journal Nature on the basis of the new fiber polymer lithium-ion battery with high safety and high performance. However, how to prepare fiber polymer energy storage batteries quickly and on a large scale is a bottleneck problem in the field of smart fibers for a long time. But Mr. Peng Huisheng's team is willing to "bite the bullet". Because of completely different device structures, electrode preparation and device construction methods for bulk lithium ion batteries are difficult to apply to fiber lithium batteries, and research on continuous preparation of fiber lithium batteries is almost blank in the world. However, after persistent research, the team found a new route for large-scale production of fiber batteries.

Just last year, relevant research achievements were published online in Nature Nanotechnology under the title of Industrial scale production of fiber batteries by a solution extrusion method. Previously, the preparation of fiber batteries was mostly based on the preparation method of planar batteries. Through the layer by layer coating process, the fiber batteries produced had poor performance and low production efficiency, which could not meet the requirements of practical applications. The biggest difficulty lies in how to maintain the stability of the interface between the functional components of the battery and achieve electrochemical activity in such a fine and soft fiber structure.

In this work, the team successfully integrated the preparation of fiber polymer energy storage battery with the classic wet spinning method. The fiber battery prepared by the large-scale, one-step method of polymer wet "spinning" is thinner and softer, and more close to the high molecular chemical fiber used in daily textile, which has realized the rapid and continuous construction of a series of kilometre fiber batteries. And the subsequent experimental results also showed that, even if the fiber battery was prepared continuously at a high production rate, the obtained functional components in the fiber battery also had good interface stability, thus showing good electrochemical performance.

The productivity of this new preparation method is more than 250m/h, previously, the productivity was only 60m/h. Finally, the team weaved the fiber battery into a tent covering an area of 10 square meters. After testing, the energy density of the tent was 550 mWh/m.

The fiber lithium battery is developed based on the previous light-emitting fiber products, with the purpose of enabling the textile fiber to have the function of energy storage. Compared with traditional batteries, this kind of new battery system material has just appeared in recent years, and the volume expansion, structural stability, battery capacity, cycle performance and other aspects in the charge and discharge process still need further research and verification.

At present, there are few research groups studying fiber battery in China. I hope that more scholars can devote themselves to this field in the future, and I hope that "battery on body" will be realized as soon as possible.