Energy density analysis of various battery types

Portable electronic devices are powered by batteries. With the rapid development of portable products, the usage of various batteries has greatly increased, and many new types of batteries have been developed. In addition to the familiar high-performance alkaline batteries, rechargeable nickel-cadmium batteries, nickel-hydrogen batteries, and lithium batteries have been developed in recent years. It is important to analyze the basic knowledge of lithium batteries. This includes its characteristics, important parameters, the meaning of the model, the scope of application and precautions for use. Energy density of various battery types Lithium is a metal element, and its chemical symbol is lithium. Lithium is a silver-white, very soft, chemically active metal. In addition to its applications in the atomic energy industry, it can also be used to make special alloys, special glass (fluorescent glass for TV sets) and lithium batteries. In lithium batteries, it is the anode of the battery. Lithium batteries are also divided into two categories: non-rechargeable batteries and rechargeable batteries. Non-rechargeable batteries, also known as disposable batteries, can only convert chemical energy into electrical energy once, and cannot restore electrical energy to chemical energy (or have poor reduction performance). Rechargeable batteries are called secondary batteries (also called accumulators). It can convert electrical energy into chemical energy for storage. In use, chemical energy is converted into electrical energy. It is reversible, such as electrical energy, chemical energy, lithium batteries and other important features. The cathode material of lithium batteries is usually composed of lithium active compounds, while the anode material is carbon with a special molecular structure. The commonly used anode material is LiCoO2. When charging, the added potential of the battery pole forces the compound of the positive electrode to release lithium ions, which are embedded in the carbon arranged in a sheet structure. During the discharge process, lithium ions are separated from the layered carbon and recombine with the positively charged compound. Electric current occurs in the movement of lithium ions. Although the principle of the chemical reaction is very simple, more practical issues must be considered in actual industrial processing: the material with positive electrode needs additives to maintain the activity of multiple charge and discharge; the negative electrode material should be designed at the molecular level to accommodate More lithium ions; the electrolyte filled between the positive electrode and the negative electrode must not only be stable, but also have good conductivity to reduce the resistance of the battery. Lithium batteries rarely have the memory effect of nickel-cadmium batteries. The memory effect is achieved through crystallization, and it rarely occurs in lithium batteries. However, the capacity of lithium batteries is still decreasing after multiple recharges, and the reasons are complex and diverse. This is important due to changes in the anode and cathode materials themselves. From a molecular level, the positive and negative hole structures containing lithium ions will gradually collapse and be blocked. From a chemical point of view, it is the passivation of positive and negative materials, and other compounds that are stable in side reactions. There are also some physical conditions, such as the gradual peeling of the anode material, which ultimately reduces the amount of lithium ions in the battery, allowing it to move freely during charging and discharging. Disclaimer: Some pictures and content of articles published on this site are from the Internet, please contact to delete if there is any infringement. Previous: Introduction to lithium battery repair methods