The power cell's pursuit of energy density is more risky than Tesla is not necessarily a benchmark.

Tesla has been earning attention again in the past two days. Tesla recently provided details of its model 3 battery technology, including the mix of raw materials currently used in its batteries, in a shareholder e-mail, foreign media reported.

Earlier, Musk claimed that the 21700 lithium battery single energy density that was first used in Model 3 was close to 300 watts/kg, which is almost the world's highest mass production lithium ion battery. It remains to be seen whether Tesla will be the world's biggest player again.

China accounted for about half of global sales of new energy vehicles in the first quarter of 2018, according to US media. Tesla claims its latest battery can last up to 20 minutes and last 350 kilometers. With such a huge market, can China build similar SUPERBATTERIES? Batteries used in new energy vehicles in China have not yet dominated the world. Are they limited by manufacturing materials or key technologies? Or did you choose a different technology route?

Challenge no limit chase energy density ratio is risky

"Tesla claims that the maximum energy density of the battery is 300 watts/kg. The higher the battery energy density, the higher the chance of a combustion explosion. "Zhangyu, Secretary General of the Power Battery Application Branch of the China Chemical and Physical Power Industry Association, said that the core of the battery is the battery management system, although Tesla has better solved the problem of thermal runaway caused by energy density increase through battery system management technology. And through the car design successfully circumvented the three-way lithium battery cycle life of the problem. But further increases in energy density will pose greater challenges to battery safety management.

Tesla's claim to have the highest energy density of lithium-ion batteries is also not perfect in the eyes of industry experts.

Yangyusheng, an academician of the Chinese Academy of Engineering, emphasized on several occasions that continuously increasing the specific energy of batteries is a very dangerous road.

Prior to this, the chairman of the China Association for Science and Technology has publicly stated that from the market point of view, mileage renewal is indeed an important symbol of the technological progress of electric vehicles, but its realization is not a simple solution to increase the number of car batteries.

"The greater the energy density of the battery, the greater the amount of electricity stored per unit volume, and the energy density and load of the battery determine the endurance of the electric car. In the past decade, the increase in battery energy density has mainly been achieved by the technological advancement of battery materials and the increase in the proportion of active substances in batteries. "Yangxulai, deputy director of the engineering research institute of Hefei Guoxuan Gaoke Power Energy Co., Ltd., said that by increasing the size of the battery to reduce the weight of the auxiliary material such as the shell, the effect of increasing the battery energy density can also be achieved.

For the new energy industry, which is responsible for the task of overtaking the National curve, the importance of power batteries is self-evident. Many industry insiders admit that power batteries are the heart of new energy vehicles, and how far new energy vehicles can go depends mainly on power batteries.

It is worth noting that according to the "Made in China 2025" power battery development plan: by 2020, the domestic battery energy density will reach 300 watt/kg. Experts believe that China is actively promoting the development of high-specific energy batteries, but the relationship between battery safety and energy is still worth studying.

Technology has problems. Local companies can make it.

Industry experts say that not only is Tesla's battery-system control capability, but vehicle design is not something most Chinese companies can emulate and surpass in the short term. So will Chinese companies be able to build triple-lithium batteries as robust as Tesla?

In the four main materials of the battery-positive materials, negative materials, electrolytes, and diaphragm, positive materials not only account for 40 inches of cost, but also directly determine the energy density of the core. According to the positive material technical route, power cells can be mainly divided into three types: lithium iron phosphate, lithium ternary(NCA/NCM) and lithium manganese.

According to the composition of the positive electrode material, the ternary lithium battery is divided into NCA and NCM. NCM means that the positive electrode material is composed of three types of nickel cobalt manganese materials in a certain proportion, and the NCA positive electrode material is composed of nickel cobalt aluminum. Tesla's claimed strong battery life belongs to the triple-lithium NCA battery.

Zhou Bo, director of the Research Department of the Power Battery Application Branch of the China Chemical and Physical Power Industry Association, said that NCA's production process conditions are more stringent and the production process has a threshold. More importantly, the technical barriers to NCA materials are also very high. At present, production capacity is mainly concentrated in Japan and South Korea, and China's mass production is relatively small.

"NCA batteries can also be done at home. Last year, a key domestic material company supplied more than 1,000 tons to Matsushita, Japan. " said Zhangyu.

However, according to the reporter's understanding, the industrialization and development of domestic NCA materials and their batteries started late. At present, many companies have begun trials and trials in small batches. There are still some technical problems that need to be solved, and no mass production and sales have taken place. At the same time, the production of materials is limited, and the foreign NCA material market is mainly monopolized by Sumitomo Metals and Japan Chemical Industry Co., Ltd..

Zhangyu analyzed that the deep reason why NCA batteries have not been mass-produced in China is also that the safety of batteries due to poor thermal stability has decreased, and battery manufacturers and terminal product users have concerns about the safety of NCA batteries. This requires reliable security design from the power core design, power supply system design, power supply use and other links. From the processing point of view, NCA batteries require a pure oxygen environment and high processing costs. In the whole process of battery production, humidity must be controlled below 10, which poses great challenges to domestic companies.

Because of technology, cost and subsidies, China has mainly chosen the NCM route, but this does not mean that the NCA route does not have new opportunities.

Cost affects the market Tesla is not necessarily the benchmark

Although Chinese companies are not unable to build lithium ternary batteries, Tesla's challenge to limit lithium ternary batteries is not necessarily the only goal of research and production of new energy car batteries in China.

According to data from the Power Battery Application Branch of the China Chemical and Physical Power Industry Association, from the perspective of different battery materials, the installed capacity of the lithium battery in January to December 2017 was 16.04 GW, accounting for 44.01 <UNK>; The installed capacity of lithium iron phosphate batteries was 17.97 GW, accounting for 49,29 <UNK>; Lithium manganese acid battery installed capacity of 1.48 gigawatts, accounting for 4.06 <UNK> ...

Industry insiders told the science and technology daily reporter that under the leadership of national policy and market environment, China's lithium-ion battery technology route is equal to lithium-phosphate and ternary lithium-ion batteries. However, even in the development of the technical route of the three-way lithium battery, the choice of domestic power battery manufacturers also has a focus on the selection of the NCM route, and few choose the NCA route used by Tesla.

The NCA battery has been mass-produced and mature, and has been commercially verified; The NCM battery with high energy density has not yet been mass-produced. Industry experts said that the performance of the two is relatively close, but NCM with high energy density is slightly cheaper. Therefore, from the value of value, NCM is more in line with our market.

"In a sense, it is actually lithium iron phosphate that makes China's new energy cars. From the cost point of view, lithium iron phosphate is more dominant. We predict that in the future, lithium iron phosphate batteries should have more market space than lithium trioxide batteries. "Yangxu told the Science and Technology Daily that at this stage, the development trend of Sanyuan lithium batteries has benefited from the National policy-oriented requirements for high-specific energy batteries, requiring high battery energy density and long range of life. Of course, the three-way lithium battery has higher specific energy and specific power, which is more in line with the passenger car's needs, but it is not necessarily the mainstream of the market in the future.

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