Views: 202 Author: Hedy Publish Time: 2023-06-07 Origin: Site
The negative electrode is metallic lithium, the positive electrode is heat treated electrolytic manganese dioxide, and the electrolyte is lithium perchlorate dissolved in mixed solvents such as propylene carbonate and ethylene glycol dimethyl ether.When compared to other lithium batteries, the Li MnO2 cell has low material and production costs as well as high safety, making it the most frequently used commercial lithium ion battery in the world today.
The negative electrode is metallic lithium, the positive electrode is heat treated electrolytic manganese dioxide, and the electrolyte is lithium perchlorate (or lithium triflate) dissolved in mixed solvents such as propylene carbonate and ethylene glycol dimethyl ether. Its discharge method differs from normal batteries' oxidation-reduction mechanism, and the positive electrode reaction is a typical insertion reaction.
When the battery discharges, the lithium negative electrode undergoes an oxidation reaction, producing lithium ions that dissolve in the electrolyte solution and migrate to the manganese dioxide positive electrode, where they embed into the manganese dioxide lattice and promote manganese reduction from four to three valence states.
1. Low cost: The positive electrode active material manganese dioxide employs electrolytic manganese dioxide, a reasonably inexpensive material among lithium battery positive electrode active materials that may be extensively promoted and deployed.
2. Excellent battery performance: the specific energy of a manganese dioxide primary lithium battery is 5-10 times that of dry batteries (about 230wh/kg or 500wh/l), the load voltage is 2.8V, and the discharge voltage is relatively stable. It can work in the range of -40℃ to +50℃;
3. Long battery storage life: The battery storage life at room temperature is more than 10 years, and the annual capacity loss is about 1%;
4. Safe and reliable battery: The battery does not generate gas during storage and discharge, and has good safety;
5. Various battery types: The batteries include button batteries, cylindrical batteries, and rectangular batteries, each with varied sizes and constructions, and capacities ranging from tens of milliamperes to hundreds of amperes. As a result, it may suit the needs of a variety of applications.
The earliest commercialized lithium-ion batteries were cylindrical in shape. They have the highest degree of automation and the lowest cost when compared to pouch and rectangle lithium-ion batteries.Lithium iron phosphate, lithium cobalt oxide, lithium manganese oxide, manganese cobalt mixed material, and ternary system cylindrical lithium-ion batteries are classified, and the shell is classified as steel shell or polymer shell. distinct battery material technologies offer distinct advantages.The important cylindrical body currently uses steel-shell cylindrical lithium iron phosphate batteries, which have large capacity, high output voltage, good charge and discharge cycling performance, stable output voltage, stable electrochemical performance, safe operation, a wide operating temperature range, and environmental friendliness.
The unit is mainly composed of positive electrode, negative electrode, separator, positive and negative current collectors, safety valve, overcurrent protection device, insulation, and shell. The shell, which was mostly made of steel in the early days, is currently mostly made of aluminum.
The design of overcurrent protection devices varies among manufacturers and can be customized according to different safety requirements and at different prices. Common safety devices include PTC positive temperature coefficient resistors and fuse devices.When overcurrent occurs, the resistance heats up, and the accumulation of temperature promotes the rise of PTC resistor value. When the temperature exceeds the threshold, it will suddenly increase, which isolates the faulty unit from the entire circuit and prevents further thermal runaway.In principle, a fuse is a fuse. When there is too much current, the fuse blows and the circuit is disconnected.The difference between the two protection devices of lithium-ion batteries is that the former can be restored, while the latter is a disposable protection. Once a fault occurs, the system must consider replacing the problem unit to make it work normally.