As a highly potential power solution in modern electronic devices, the polymer lithium battery has a design principle that is closely linked to its material basis, which together endows the battery with bendability.
First of all, from the design principle point of view, the polymer lithium battery abandons the structural design of traditional rigid batteries. It adopts a thin-sheet structural layout, and thins key components such as positive and negative electrode materials, electrolytes, and current collectors. For example, the positive and negative electrodes usually use active material films coated on flexible substrates. This design reduces the overall thickness and rigidity of the battery, allowing it to adapt to bending deformation to a certain extent. At the same time, the internal connection structure of the battery is also specially designed, such as using flexible circuit boards or bendable electrode connection methods to ensure the stability of electron transmission during the bending process, and avoid problems such as circuit breakage or poor contact caused by bending.
In terms of material basis, the selection of electrode materials is crucial. For positive electrode materials, some transition metal oxides or phosphate materials with good flexibility have been widely studied and applied. For example, lithium iron phosphate materials have become an important choice for positive electrode materials of polymer lithium batteries due to their structural stability and relatively good flexibility. For negative electrode materials, new carbon materials such as graphene and carbon nanotubes have shown excellent performance. They not only have high conductivity, but also their own nanostructure gives them good flexibility and mechanical strength, and can withstand repeated bending without breaking or significant performance degradation.
Electrolyte materials are also a key factor in determining flexibility. Polymer electrolytes are widely used because of their good plasticity and compatibility with electrodes. For example, polyethylene oxide (PEO)-based polymer electrolytes form ion conductive channels by adding an appropriate amount of lithium salts. While ensuring the ion transmission capacity, they can deform as the battery is bent to maintain good contact between the electrolyte and the electrode.
In addition, the packaging material of the battery should not be ignored. Thin film materials with high barrier properties and flexibility, such as aluminum-plastic composite films, are usually selected. This material can effectively prevent the intrusion of external moisture and oxygen and protect the internal components of the battery. At the same time, its own flexibility prevents the packaging layer from breaking when the battery is bent, ensuring the overall stability and safety of the battery. In summary, polymer lithium battery achieves bendability through unique design principles and special material selection, laying a solid foundation for its application in many fields such as wearable devices and flexible displays.
