Lithium-manganese batteries generally refer to lithium-manganese dioxide batteries. Lithium-manganese dioxide batteries are a type of battery that uses lithium as the negative electrode and manganese dioxide as the positive electrode. Manganese dioxide batteries have good low- and medium-rate discharge performance, are inexpensive, and have good safety performance, making them competitive with conventional batteries. Therefore, they were the first type of lithium battery to be commercialized.
Manufacturing process of lithium manganese dioxide batteries
The following example, a fully sealed cylindrical wound lithium manganese dioxide battery, illustrates the basic manufacturing process and flow of this type of battery.
1. Preparation of manganese dioxide cathode
Heat-treated electrolytic manganese dioxide powder is mixed with acetylene black, polytetrafluoroethylene emulsion, and isopropanol in a certain proportion and stirred to form a paste. The paste is then evenly coated onto a metal current collector, heat-treated, and rolled to form an electrode. Alternatively, the prepared positive electrode paste is heated and placed on both sides of a metal current collector, then rolled using a roller mill to form the electrode. The prepared electrode should be placed in an environment with an air humidity of less than 20% (10% humidity).
2. Preparation of lithium metal anodes
Select lithium strips of appropriate thickness and width according to different battery models, cut them to the required length, and then cold-weld the tabs onto the cut lithium strips. Anode preparation must be carried out in an environment with a relative humidity of less than 2%.
3. Preparation of the diaphragm
After drying, the polypropylene diaphragm that meets the thickness and width requirements is stored in an environment with a humidity of less than 2% for later use. Composite diaphragms that can close at 130~160℃ are usually selected.
4. Preparation of battery cells
In an environment with humidity less than 2%, two layers of separators, slightly wider than the electrodes, are wrapped around both sides of the manganese dioxide positive electrode to separate the positive electrode from the lithium negative electrode. Then, the separator is wound into a core on a winding machine and placed inside the battery casing. This is the winding structure of a lithium manganese dioxide battery core.
5. Preparation of electrolyte solutions
Electrolyte solution formulations vary among manufacturers, but the basic preparation method involves mixing dehydrated lithium perchlorate with purified propylene carbonate, ethylene glycol dimethyl ether, and other ingredients in a specific ratio. The preparation of the electrolyte solution requires a dry air environment with humidity levels below 2%.
6. Electrolyte solution filling and filling port sealing welding
First, weld the top cover with glass insulators to the shell containing the electrode core. Then, use a liquid injection machine to inject the specified weight of electrolyte solution into the battery through the injection hole, and use a steel ball to plug the hole by welding.
