A lithium battery is a type of rechargeable battery that uses lithium compounds as the electrode material. It mainly includes lithium-ion batteries and lithium-metal batteries. Lithium-ion batteries have a lithium-ion intercalation compound as the cathode and a carbon material as the anode, and the lithium ions move between the cathode and anode during the charge and discharge process. Lithium-metal batteries use lithium metal as the anode and a lithium-ion intercalation compound as the cathode.
In the 1970s, the research on lithium batteries began. In 1970, Exxon's M. S. Whittingham developed the first lithium-ion battery using titanium disulfide as the cathode and lithium metal as the anode. However, due to the safety problems of lithium metal anodes, the development of lithium-ion batteries entered a new stage in the 1980s and 1990s. In 1989, Sony commercialized the first lithium-ion battery using a lithium cobalt oxide cathode and a graphite anode, which opened the prelude to the wide application of lithium-ion batteries. Since then, the technology of lithium-ion batteries has continued to develop and improve, and new cathode and anode materials have emerged continuously, improving the performance and safety of lithium-ion batteries.
During the charging process of a lithium-ion battery, the lithium ions in the cathode material are deintercalated and move to the anode through the electrolyte under the action of an external electric field and are inserted into the anode material. At the same time, electrons are transferred from the cathode to the anode through the external circuit. During the discharging process, the reverse reaction occurs. The lithium ions in the anode material are deintercalated and move to the cathode through the electrolyte, and electrons are transferred from the anode to the cathode through the external circuit, generating an electric current to power the external device.
1. High energy density: Lithium-ion batteries have a much higher energy density than traditional lead-acid batteries and nickel-cadmium batteries, which means that they can store more energy in a smaller volume and weight, making portable electronic devices and electric vehicles more compact and lightweight.
2. High voltage: The nominal voltage of a lithium-ion battery is generally about 3.6V or 3.7V, which is much higher than that of traditional batteries such as nickel-cadmium batteries (1.2V) and alkaline batteries (1.5V). This allows for a simpler circuit design and reduces the number of cells required in series for some devices.
3. Low self-discharge rate: The self-discharge rate of lithium-ion batteries is relatively low, usually less than 5% per month. This means that the battery can maintain its charge for a long time when not in use, reducing the frequency of recharging.
4. Long cycle life: Under normal use conditions, lithium-ion batteries can generally be cycled hundreds of times or more. With the continuous improvement of technology, some high-quality lithium-ion batteries can even reach thousands of cycles, greatly reducing the cost of battery replacement.[!--empirenews.page--]
5. No memory effect: Unlike nickel-cadmium batteries, lithium-ion batteries do not have a memory effect. That is, they do not need to be fully discharged before charging and can be charged at any time without affecting the battery's capacity and performance.
6. Some safety risks: Although the safety of lithium-ion batteries has been continuously improved, there are still some potential safety risks, such as overcharging, overheating, short-circuiting, and mechanical damage, which may cause the battery to catch fire or explode. Therefore, strict safety management and protection measures are required during the use and storage of lithium-ion batteries.
Some common terms in lithium battery technology include anode, cathode, electrolyte, separator, capacity, voltage, current, charge-discharge rate, cycle life, self-discharge rate, energy density, power density, cathode material, anode material, lithium-ion intercalation compound, etc. Understanding these terms is helpful for better understanding and using lithium batteries.