Structure of lithium battery
Lithium batteries usually have two shapes: cylindrical and square.
Spiral wound structure is adopted inside the battery, and a very fine and highly permeable polyethylene film isolation material is used to separate the positive and negative electrodes.
The positive electrode includes a current collector composed of lithium cobalt oxide (or nickel cobalt lithium manganate, lithium manganate, lithium ferrous phosphate, etc.) and aluminum foil.
The negative electrode is composed of a current collector composed of graphitized carbon material and copper foil. The battery is filled with organic electrolyte solution.
In addition, it is also equipped with safety valve and PTC element (some cylindrical use), so as to protect the battery from damage in case of abnormal state and output short circuit.
The voltage of a single lithium battery is 3.7V (3.2V for the positive electrode of lithium ferrous phosphate), and the battery capacity cannot be infinite. Therefore, a single lithium battery is often treated in series and parallel to meet the requirements of different occasions.