Energy density analysis of various kinds of cell types

Source: 2020 - 03 - 28 'hits: time is by the battery power portable electronic devices. With the rapid development of portable products, all kinds of battery usage increased greatly, and have developed many new battery. In addition to the people familiar with the high-performance alkaline batteries, developed in recent years to rechargeable nickel cadmium battery, nickel metal hydride batteries, lithium batteries, etc. Mainly introduced the basic knowledge of the lithium battery. Including its features, main parameters, the meaning of the model, the application range and use the matters needing attention. All kinds of lithium battery types of energy density is a kind of metal elements, it is the chemical symbol of lithium. Lithium is a silvery white, very soft, has the chemical activity of the metal. In addition to the application of atomic energy industry, it also can be used to make special alloys, special glass ( Used in TV fluorescent glass) And lithium battery. In the lithium battery, it is the battery anode. Lithium-ion batteries are divided into two categories: don't charge the battery and rechargeable battery. Don't charge the battery, also known as disposable batteries, it only can convert chemical energy into electrical energy, reduction cannot be electric energy to chemical energy ( Or reduction performance is very poor) 。 Rechargeable batteries are called secondary battery ( Also known as a battery) 。 It can store electrical energy is converted into chemical energy, in use, and then convert chemical energy into electrical energy, and it is reversible, such as electric power, chemical, and other main characteristics of lithium battery. Lithium ion battery cathode material is usually consists of lithium active compounds, the anode materials is with special molecular structure of carbon. Commonly used anode material is LiCoO2. When charging, batteries extremely potential force increased by positive compounds releasing lithium ion, lithium ion embedded in carbon with lamellar structure arrangement. In the process of discharge, lithium ion separated from laminar carbon, combined with positively charged compounds again. An electrical current lithium ion movement. Although the chemical reaction principle is very simple, but in the actual industrial production also need to consider more actual problem: with the anode material additives are needed to maintain the activity of repeatedly charging and discharging, Anode materials need to be designed at the molecular level, in order to accommodate more lithium ions; Filling the electrolyte between the positive and negative, in addition to stability, also need to have good electrical conductivity, reduce the resistance of the battery. Lithium ion batteries have few nickel cadmium battery memory effect, memory effect is done by crystallization, is also rare in the lithium ion battery. However, lithium ion battery after repeatedly charging capacity is still falling, the reason is complicated. This is mainly due to the change of the anode and the cathode material itself. Look from the molecular level, the positive and negative on lithium ion hole structure will gradually collapse and blocked. From the chemical point of view, it is the positive and negative material passivation, side effects produce stable of other compounds. There are also some physical conditions, such as the anode material of stripping gradually, finally reduces the amount of lithium ion batteries, make its can move freely in the process of charging and discharging.