Lithium iron phosphate is out of date?

As "twelfth five-year" national 863 program, the electric car steering teeg expert huang is mainly engaged in lithium secondary battery and its related materials, process and equipment technology research, he pointed out that the development of the power battery in our country there are two major technology route, respectively for commercial vehicles and passenger cars, commercial vehicles mainly choose the lithium iron phosphate batteries, expected this year could exceed 160 Wh/kg; And passenger car because the energy contrast has high requirements, so the ternary material attract more batteries, the battery monomer ratio energy can achieve 220 Wh/kg, and battery pack system can achieve 150 Wh/kg.

However such specific energy and can't meet the requirements of people to travel distance is longer, so they continue to experiment with different materials. Huang, in addition to the cobalt acid lithium applications on mobile phones, other manganese acid lithium, lithium iron phosphate, ternary material, high nickel rich lithium has certain advantages in different extent.

The NCA ternary material due to its monomer high specific energy, long storage life, by some favour, French was the SAFT will this material to use on the satellite, batteries today, tesla is also equipped with NCA batteries. But on the other hand NCA cycle life is lower, more important is its poor safety performance. Although monomer is higher than the energy, but the specific energy of group after is greatly reduced. Travel distance in order to ensure the longer, the inevitable need more amount of monomer, so will produce certain hidden trouble in security.

Huang of the above several kinds of material of battery made a detailed comparison of cobalt acid lithium while performance is good, but the cost is very high, so only used in the mobile phone; Lithium manganese acid cost is low, the current in the field of commercial vehicle demand is more, but lower than the energy, so the car at low speed, the comparison of the two rounds of car. Comprehensive comparison, it seems, huang believes that the lithium iron phosphate long cycle life, security, stability is strong, the cost is also reduced gradually, so still is the mainstream of choice.

For this point of view, also was the attitude of ai. Participated in national ministry of science and technology "new energy vehicles to" guide written by he resolutely opposed to the travel distance in order to increase and the practice of blindly increasing the weight of the battery, because this kind of practice will lead to overall vehicle weight buoyancy, so also will increase energy consumption, make electric cars but not environmental protection, and it also dramatically increased costs, not conducive to marketing.

So ai stressed that the overall development direction of power battery, must satisfy the safety, long life, greatly enhance specific energy indices such as cycle life. Comprehensive comparison of various materials battery, he also thinks the lithium ion battery is still the key point of the development of the power battery.

How to improve the ratio of the lithium iron phosphate energy?

Huang, continue to research and development is not the focus of the lithium iron phosphate material itself, but rather in the design of the battery and the anode materials of form a complete set. Lithium iron phosphate, in his opinion, after years of development, has formed the annual output of 100000 tons of production capacity and material technology has been very mature. So you need to focus on research of anode materials for lithium iron phosphate is what kind of can better play to its good performance.

Huang two materials, for example, one kind is can quick charge under low temperature, the other is a can have higher specific energy. Can quick charge of graphene materials under low temperature, have higher specific energy is silicon carbon material, and must be nanoscale silicon.

, ai said, want to increase the specific energy of the lithium iron phosphate, we must solve the cycle of silicon anode coulomb efficiency low and rich lithium manganese base voltage attenuation problem, is expected to develop specific energy breakthrough 400 wh/kg of advanced lithium ion power battery. And from a long-term point of view, innovation type lithium ion battery is lithium lithium sulfur, empty more realistic feasibility. He argues that the development based on anionic charge compensation mechanism of high volume rich lithium oxide anode (350 mah/g) or higher, can develop specific energy is greater than 500 wh/kg power battery.

Ai emphasize security determines the high energy battery loading application prospect of development of spontaneous thermal control technology and solid-state batteries are feasible solution, so must intensify research. And high capacity of electrodes is the basis of the ratio of high to realize the battery can, according to the polarization model, development gradient porosity electrode, the ratio can battery development plays an important role and significance.

Lithium iron phosphate advantage more

Huang, now a new generation of lithium iron phosphate battery monomer has specific energy can reach 175 wh/kg, after the group can meet the requirements of commercial vehicle 150 wh/kg. Along the route, in his opinion, continue to research and development, in 2020 the lithium iron phosphate battery pack achieve 180 wh/kg is achievable, and there are larger development space. Huang also pointed out that the lithium iron phosphate in China's industrial base is strong, not only is heavier, in commercial, also has the application space in terms of energy storage.

In addition to this, ai, solid-state batteries is the inevitable trend of the future, and solid-state batteries fight oxidation ability, low temperature conductivity and so on all have higher requirements, and now popular ternary material, such as cobalt acid lithium is not possible, only the lithium iron phosphate batteries can meet.