Since its invention, lithium-ion batteries have been widely used in 3C electronic products. With the development of smart wearable electronic devices, the demand for ultra-thin lithium-ion batteries is increasing. Currently, ultra-thin batteries are thinner than paper and can be bent and folded for use.
1. Ultra-thin lithium-ion battery
The thickness of lithium-ion batteries is usually measured in millimeters because of the different material properties of lithium-ion batteries. With the improvement of lithium-ion battery production technology, ultra-thin lithium-ion batteries can be made under 1mm, Greg's battery now, after years of research and development, production technology continues to improve production innovation, the production of lithium-ion batteries can reach 0.4mm, The thinnest shape and size can be customized according to the needs, and the ultra-thin lithium-ion battery can also have a certain curvature at the same time. In terms of energy density, under the same competitive product, the same shape and size, with higher capacity and discharge capacity, with longer battery life. Of course, high traffic can also be achieved.
2. New flexible and foldable thin batteries
In recent years, with the development of battery technology, a battery that can be bent and deformed when folded has been invented.
A new type of flexible thin battery
(1) South Korean researchers have created a paper-thin battery, which holds promise for wearable devices to break through the battery bottleneck. It is also called a paper battery because of its flexibility.
According to reports, the production materials of this paper battery are mainly from wood. First, cellulose is extracted from wood, and then the cellulose is divided into 10,000 pieces the size of hairs, which are used as raw materials to make the electrodes and separators of lithium electronic batteries. Because of the material, the battery is like a piece of paper, so soft that it works even when the paper crane is folded, which allows it to be installed in more complex device interior spaces.
The advantages of batteries are obvious and a good choice for smart devices. At the same time, the invention of paper batteries means that future smart devices will have ultra-thin bodies and super battery life.
(2) The research group from the Swiss Federal Institute of Technology in Zurich (ETH Zurich) finally made all the internal structures of lithium-ion batteries bendable, twisting has replaced new materials, and the world's first can bend and stretch arbitrarily. The lithium-ion battery is an identical foldable solid-state lithium-ion battery according to the sandwich structure. By solid lithium ion battery, I mean that the electrolyte used to transfer lithium ions in the battery is not a solution of the above organic solvent and lithium salt, but a solid, a special substance between liquid and solid water gel.
Hydrogel is a hydrophilic three-dimensional polymer network structure gel. On the one hand, it has rubber-like properties with a large number of cross-linked organic polymer chains, usually connected by covalent bonds, hydrogen bonds or electrostatic forces. The hydrogels Chen and his team chose are cross-linked by the strongest covalent bonds, so when each polymer chain is stretched, there is no relative slip between them due to the strong covalent bonds. When the tension is removed, the polymer chains contract and the object returns to its original shape. Without this covalent bond, the slippage between chains during stretching would eventually cause the material to fracture beyond recovery.
On the other hand, the hydrophilic character allows the hydrogel to carry a large amount of water. The researchers dissolved the hydrogel with an appropriate ratio of highly water-soluble lithium.
Of course, battery technology still has a long way to go before large-scale commercial application.
1. The performance of this battery technology cannot yet significantly increase the energy density compared with mature commercial batteries;
2. Battery technology should continuously optimize charge and discharge control, improve packaging process, and prolong its cycle life;
This battery technology will reduce the cost of batteries. As the world's first bendable full battery, the cost of some of its materials makes it difficult to compete commercially with mainstream batteries.
