There are many positive materials of lithium-ion batteries, according to the different positive materials, can be divided into lithium cobalt acid, lithium manganese acid, triple material, lithium iron phosphate lithium titanate. Triple lithium battery refers to the use of nickel, cobalt, manganese three transitional metal oxides as positive materiallithious battery, because it combines lithium cobalt acid, lithium nickel lithium manganese acid three kinds of materialadvantages, the performance is better than the first single component of positive materials. Experimental analysis shows that three different elements of price-sharing form a super-crystalline structure, there is a clear synergy between the three components, making the material more stable, the discharge platform as high as 3.6V, so it is considered to be one of the most promising positive materials. Triple batteries have high energy density, good safety stability, support high-efficiency discharge other excellent electrochemical characteristics, as well as affordable cost advantages, in consumer digital electronic products, industrial equipment, medical equipment other small medium-sized lithium battery field has been widely used, in intelligent robots, AGV logistics vehicles, drones new energy vehicles other power lithium battery fields showed strong development potential.
At present, the research on ternary materials mainly focuses on the preparation of precursor seishemers, the synthesis of materials the relationship between electrochemical properties structure. Most of the transition metal elements in this material Ni, Co, Mn exist in the price of 2, 3, 4, respectively, in the process of charge discharge, the electrochemical reaction occurred only Ni2 plus/Ni4 plus Co3 plus /Co4 plus, Mn basically does participate in the electrochemical reaction, but plays the role of stabilizing the material structure. Regarding the preparation method, the commonly used synthesis methods in industry are: high temperature solid phase method, co-precipitation method, sol-gel method, hydrothermal synthesis method, combustion method, etc. Three-way material is a comprehensive superior performance of lithium battery positive material, in a certain range to change the mole ratio of three materials, add the corresponding additives (adhesives, conduction agents, set fluids, etc.), can be in a certain aspect of outstanding performance characteristics, such as power-type triple lithium battery, capacity-type triple lithium battery, ultra-low temperature triple lithium battery so on.
Three-cell polymer lithium battery.
The triple polymer lithium battery is a lithium battery that uses nickel cobalt manganese acid (NiCoMn) O2) a lithium battery using a gel polymer electrolyte. Electrolyte as the transfer medium of ion motion, generally composed of solvent lithium salt, lithium secondary battery electrolyte mainly has liquid electrolyte, ion liquid electrolyte, solid polymer electrolyte gel polymer electrolyte. The gel polymer electrolyte consists of polymers, organic solvents lithium salts, which are produced by mixing organic electrolytes with solid polymer substrates. Because it exists in gel form has the advantages of solid electrolyte liquid electrolyte, because the electrolyte is confined to the polymer chain, it also has a high ion conductivity (up to 10-3S/cm) over a wide temperature range. The advantage is that the diaphragm has high mechanical strength the film provides a large surface area. The thinner the film, the higher the energy density, because more active substances can be embedded in the battery. In addition, its electrochemical stability is also very good, high temperature resistance, the market for the majority of high-temperature batteries are polymer electrolytes.
Three-dollar power lithium battery.
The so-called power battery refers to the battery supports high-rate high current discharge, high power density, more energy released per unit of time. Magnification discharge capability refers to the ability to maintain battery capacity in the case of increased charge discharge multiple seis. The multiple of charge discharge is expressed in xC, 1C means that the nominal capacity of the battery can be used up at 1h, while the multiple discharge at 2C is available at 30min.
The power/multiplier performance of the battery is closely related to the design of the battery is influenced by a variety of factors, such as electrolytes, diaphragms, types of active materials, size of active particles, etc. Among these factors, the thickness of the electrode is the main factor affecting the ability of high current discharge. The multiple discharge capability can be greatly improved by thinning the electrode because the thin electrode has a smaller electron impedance ion impedance, whereas thinning the electrode results in less active material quality in the electrode therefore a reduced battery capacity. Therefore, the main technical challenge of the three-way lithium battery is to increase the ability of high current discharge without reducing capacity.
For the three-way power lithium battery, the current research is the most mature, the most mature technology is The Japanese Panasonic Company, the experimental stage has been able to achieve 30C discharge, which has successfully achieved the commercial mass production of the power type 18650 three-yuan lithium battery discharge rate of up to 12C, capacity is also up to 3300mAh. Domestic manufacturers also have a higher discharge rate, but the stability of the battery still needs to be improved, especially after a period of use, its cycle life multiple discharge capacity will be greatly reduced. There are studies reports that the efficiency of lithium batteries can be improved by particle cladding modification.
Three yuan low-temperature lithium battery.
The temperature characteristics of the battery are the indicator of battery reliability, the performance of the battery can be evaluated by changing the ambient temperature. The low temperature characteristics of lithium batteries are mainly investigated the low-temperature discharge characteristics cycle life, the main thing of low-temperature batteries is to maintain the fluidity of substances under low temperature conditions, so that lithium ions can freely shuttle between the positive negative poles, to achieve the charge discharge of the battery. For example, the use of low melting point electrolyte, reduce the particle size of the active material, will enhance the low temperature performance of the battery, because of the increase of lithium-ion channels, to a certain extent to make up for the slow movement of lithium ion at low temperatures.
At present, domestic foreign three-way lithium battery manufacturers can basically achieve -20 degrees of discharge temperature, discharge capacity of more than 50%, cycle life in about 400 times, can fully meet the ordinary electrical appliances electricity scene. But in aerospace, military equipment other special products, the north, mountains other harsh environment, lithium batteries must be able to achieve a lower discharge operating temperature to meet the harsh use of conditions. Dongguan Yuda Electronics Co. , Ltd. special core research institute, gathered a large number of electrochemistry experts industry professor, with a strong research development team, successfully developed a low-temperature -40 degree discharge, discharge capacity of up to 67%, mainly for military special applications of ultra-low-temperature lithium batteries, successfully achieve commercial mass production.