Lithium ion battery is a kind of secondary battery, which is what we call rechargeable battery. Its working principle is mainly the movement of lithium ions between the positive and negative electrodes. In the process of discharging and charging, Li+ is intercalated and deintercalated back and forth between the positive electrode and the negative electrode: When we are charging, Li+ is deintercalated from the positive electrode and inserted into the negative electrode through the electrolyte in the battery, and the negative electrode is in a lithium-rich state; During our discharge process, Li+ is extracted from the negative electrode and inserted into the positive electrode through the electrolyte in the battery, and the positive electrode is in a lithium-rich state.
We can usually divide lithium batteries into lithium-ion batteries and lithium batteries. The mobile phones and laptops we use in our daily life use lithium-ion batteries, which are usually called lithium batteries. Lithium batteries generally use lithium-containing materials as the electrodes of the battery, which is a representative of all current batteries with high performance. However, the use of real lithium batteries has many precautions and has certain risks, so it is rarely used in daily electronic products.
Lithium-ion batteries were first developed by Sony Corporation of Japan in 1990. They successfully inserted lithium ions into carbon (petroleum coke and graphite) to form a negative electrode (traditional lithium batteries use lithium or lithium alloy as the negative electrode). LixCoO2 is generally used as the cathode material, but LixNiO2 and LixMnO4 can also be used as the cathode material. The electrolyte is LiPF6 + diethylene carbonate (EC) + dimethyl carbonate (DMC). The non-toxic materials of the negative electrode are petroleum coke and graphite. During the reaction, the lithium ions are embedded in the carbon, which overcomes the high activity of lithium and solves the safety problem of traditional lithium batteries. It is precisely because of the improvement of technology that the positive LixCoO2 can achieve higher charge and discharge performance and longer service life. Simply put, the emergence of this technology has greatly improved the overall performance of lithium-ion batteries.
Currently, new energy products are being vigorously promoted around the world. Lithium-ion batteries can well replace traditional lead-acid batteries and are very popular and very good new energy products. It is expected that lithium batteries will have a large share of the market in the 21st century. The charging and discharging reaction formula of lithium ion secondary battery is: LiCoO2+C=Li1-xCoO2+LixC