You don’t need to bring a charger or power bank when you go out. You can charge your phone wirelessly through your clothes. This imaginary scenario is gradually becoming a reality. Recently, the main journal of Nature published a study by the team of Professor Peng Huisheng of the Department of Polymer Science at Fudan University. This research system reveals the variation pattern of internal resistance with length of fiber lithium-ion batteries, effectively solves the problem of interface stability between active materials and fiber electrodes, and continuously constructs new fiber polymer lithium ions with good safety and comprehensive electrochemical properties. Battery. According to the results of this research, fiber-polymer lithium-ion batteries with a length of 1 meter can effectively and continuously supply power to wearable electronic devices such as smartphones, bracelets, and heart rate monitors for a long time. At the same time, the battery has good cycle stability. After 500 cycles, the battery capacity retention rate still reaches 90.5%. When the curvature radius is 1 cm, after the battery is bent 100,000 times, its capacity retention rate is still greater than 80%.
Future wearable battery fabric concept display
Represented by lithium-ion batteries Energy storage devices are called the “heart” of modern electronic devices. Peng Huisheng’s team proposed and implemented a new type of fiber lithium-ion battery in 2013, providing a new path for energy supply for wearable devices such as smart electronic fabrics. However, fiber lithium-ion battery research has faced a key challenge for many years, that is, the mature production system for bulk lithium-ion batteries is difficult to apply to fiber lithium-ion batteries, and the international continuous preparation research of fiber lithium-ion batteries is almost blank. So far, The lengths of fiber lithium-ion batteries reported so far are all on the centimeter scale.
“Fiber lithium-ion batteries are like wool. To weave a rechargeable sweater, you must ensure that the wool is long enough.” Peng Huisheng’s team members found that to realize the continuous construction of fiber lithium-ion batteries, it is necessary to start from the source. To clarify the relationship between the internal resistance and length of fiber batteries. By extensively trying fiber current collector materials with different electrical properties, they finally revealed the change pattern in which the internal resistance of fiber lithium-ion batteries first decreases and then gradually becomes stable as the length increases, providing strong theoretical support for the continuous construction of fiber lithium-ion batteries. .
On this basis, it is also necessary to achieve efficient and continuous preparation of active materials for fiber-loaded lithium-ion batteries. “The classic method is flat coating, but coating on the surface of the fiber can easily produce an uneven beaded structure, which is very detrimental to battery performance and stability.” said He Jiqing, a team member and a doctoral student in the Department of Polymer Science at Fudan University.
To this end, the team developed a new method to effectively solve the problem of interface stability between polymer composite active materials and conductive fiber current collectors by regulating the components and adhesion of positive and negative active materials, and achieved high loading capacity. , positive and negative fiber electrode materials with uniform coating and highly matched capacity. Subsequently, the team successively carried out methodological research on continuous battery assembly and packaging, and finally achieved the continuous and stable preparation of high-performance fiber polymer lithium-ion batteries.
Schematic diagram of wearable battery fabric
According to reports, the team has used textile methods to Obtain high-performance large-area battery fabrics. Integrating the battery fabric and the wireless charging transmitter device can wirelessly charge smartphones safely and stably.
“Fiber lithium polymer ion batteries have shown broad application prospects, but compared with the energy density of planar batteries commonly used in daily life, this battery still has room for improvement. In addition, more advanced weaving technology is needed , weaving batteries efficiently into various clothing to make people wear them more comfortable and beautiful,” said Peng Huisheng.
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