1. high nickel ternary material
Nickel cobalt manganese has high capacity, long cycle life, low toxicity and the characteristics of cheap, moreover, has a good synergistic effect between three kinds of elements, therefore has been widely used. Used for lithium battery cathode material in the oxidation reduction in energy storage, nickel were the main components, how to improve the material to improve the content of nickel in the specific capacity of material, is one of the hot spot of current research.
In general, three yuan high nickel anode material refers to material of nickel in mole fraction is greater than 0.6, the ternary material has the characteristics of high capacity and low cost, but there is also a retention capacity is low, poor thermal stability of defects.
Through the improvement of preparation technology can effectively improve material performance. Micro-nano size and morphology structure of particles, to a great extent, decides the performance of high nickel ternary cathode material. So it is the main preparation methods of different materials to evenly spread, through the different growth mechanisms, specific surface area of nano spherical particles.
In numerous preparation methods, the coprecipitation method combined with high temperature solid phase method is the mainstream method, coprecipitation method, were first introduced in to get raw materials mixing, material particle size uniformity of precursor, and then by high temperature calcination process for surface morphology neat, easy to control the ternary material, this is the main method of industrial production.
Spray drying the coprecipitation process is simple, fast preparation, the material appearance as coprecipitation, have the potential to further study. High nickel ternary cathode material of cation and charging and discharging process of mixed phase change such as faults, by doping modification and coating modification can effectively improve. While reduce the side effects and stable structure, improve the electrical conductivity, cycle performance, ratio performance, storage performance, and performance of high temperature and high pressure, will continue to be a research hot spot.
2. rich lithium ternary material
Below three yuan the anode materials for lithium xLi2MnO3 ˙ (1 -) x LiMn1/3 ni1/3 co1/3 o2 (0.1 x 0.5) or less or less structure schematic, due to its special structure, can emerge more lithium and has the advantages of wide voltage window and high specific volume was favored by researchers in recent years.
All of this material has the characteristics of high voltage, and the first charge and discharge mechanism and subsequent charge different: for the first time, charge will cause the change of the structure, the change is reflected in the charging curve has two 4.4 V as the boundary of different platforms, the second time in the process of charging, the charging curve is different from the first curve, because for the first time in the process of charging Li2O from layered structure Li2MnO3 irreversible emerge, at around 4.5 V platform.
Using solid phase method, sol-gel method, hydrothermal method, spray pyrolysis, and different structure was prepared by coprecipitation method can with rich lithium ternary cathode material, which use more is coprecipitation method, and all have their respective advantages and disadvantages of each method.
Rich lithium ternary material shows a good application prospect, is the next generation high volume one of the key materials for lithium ion batteries, but for large scale applications.
The material of the future research direction are mainly the following several aspects:
(1) to take off the lack of understanding of the intercalated-li mechanism cannot explain material coulomb efficiency will be low, the phenomenon such as large difference of material properties;
(2) the doping elements study enough, a single;
(3) due to the high voltage anode material erosion by electrolyte, caused by poor circulation stability;
(4) commercial application is less, in the aspect of safety performance of comprehensive enough.
3. single crystal ternary cathode material
Lithium electricity ternary material under high voltage, with the increase of cycling times, secondary particles or late state reunion single crystal may appear a particle boundary flour or reunion state of single crystal separation phenomenon, caused by internal resistance greaten, quick battery capacity attenuation, cyclic variation.
Single crystal type high voltage ternary material, can significantly improve the efficiency of the lithium ion transfer, and reduce the side effects between materials and electrolyte, so as to improve the cycle performance of materials under high voltage. First was prepared by coprecipitation ternary precursor material, and then under the action of high temperature solid phase, for single crystal LiNi0.5 Co0.2 Mn0.3 O2.
Material this material has good layer structure, under 3 ~ 4.4 V, 0.1 button cell discharge specific capacity can reach 186.7 m Ah/g, all the battery discharge specific capacity after 1300 cycles is 98% of the initial discharge capacity, is a kind of electrochemical performance of three yuan positive composite materials.
Up LiYe adopt unique preparation technology, designed and equipped with advanced lithium-ion battery cathode material production line, large scale production for the first time in international micron grade single crystal particles modified spinel lithium manganese acid and nickel cobalt manganese acid lithium anode material, ternary achieve yearly produces 500 tons of production capacity.