More than "Tesla" cattle lithium manganese oxide battery technology, electric car savior!

Tesla's recently launched Model 3 model is popular with the market, and improvements in battery technology have brought great market appeal to its low-cost route. Batteries have always been the primary determinant of the development of electric vehicles. Because batteries are far from comparable in energy density to internal combustion engines, mileage has become the biggest weakness of pure electric vehicles.

The range of the battery is closely related to the lithium battery, and the cathode material is an important part of the lithium-ion battery. It finally determines the capacity of the lithium-ion battery, and at the same time affects the performance of the battery and its price.

It can charge for 20 minutes and last for 350 kilometers

Keda Weilong is a company that produces electric vehicle cathode materials. The cathode material used by them is lithium manganate. The project is currently in the pilot stage. The battery using this material can be charged for 20 minutes and the battery life is about 350 kilometers. At present, the 60-degree electric version of the Tesla ModelS and the BYD e6 are both 60-degree battery capacity, which can reach a cruising range of 300 kilometers.

Tesla and BYD are good companies in battery technology. Tesla uses a nickel-cobalt lithium aluminate battery (lithium cobalt oxide battery). Among the lithium battery materials, its battery energy density is the highest, but it is also the most unstable at high temperatures. When the temperature reaches 180 degrees, the lithium cobalt acid battery will decompose into oxygen. Expose a large amount of heat energy and may explode; BYD uses lithium iron phosphate batteries. The battery material is the most stable, but the energy density is low.

Lithium manganate materials have more advantages in terms of cost price and energy density

Wang Meng, the founder of Keda Weilong, told Entrepreneurship State(WeChat: iChuangyebang) that lithium manganate was chosen because these positive materials such as lithium cobalt, ternary material, and lithium iron phosphate were either relatively low in capacity or high in price. Or contain heavy metals that are harmful to the environment. Either the cycle performance is poor, or the ratio performance is not ideal, it is difficult to meet the development needs of electric vehicles. In combination with various factors, lithium manganese acid material is the most promising lithium ion positive electrode material in terms of performance and price and environmental protection.

Lithium batteries have two key parameters, which is also an important reason for impeding mileage. The first is the cost of $/ Kwh, that is, the amount of electricity per kilowatt; The second is the energy density of the battery wh/kg, that is, per kilogram of wattage.

In terms of cost price, at present, the market price of commonly used ternary cathode materials and lithium iron phosphate is about 150,000 per ton, and the price of lithium manganate is about 70,000 yuan; Wang Meng told the entrepreneurial state that the lithium layer positive electrode material they developed is an upgrade of the current market positive electrode material. The market price of the positive electrode material is about 60,000 tons per ton, which is not only lower in price but also significantly improved in performance and more cost-effective.

In terms of energy density, the current lithium battery is about $400-500 / Kwh, that is, an electric battery costs 400-500 US dollars. According to the current exchange rate, it is probably 2500-3000 yuan per kilowatt. The battery energy density produced using lithium manganate positive electrode materials can reach 500KW/Kg, self-discharge rate 0.5 %, service life 10 years, and the cycle life of lithium iron phosphate power cells is between 7 and 8 years.

The key is raw materials and synthesis.

The structure and properties of lithium manganate cathode materials are closely related to the raw materials and calcination process conditions. The electrochemical properties of the materials prepared by different synthesis conditions (raw materials, temperature, calcination time and process lamps) are quite different, and The doping element and the doping amount are related, and the cycle decay is fast - especially at high temperatures, the attenuation is more pronounced. Therefore, the selection of raw materials and the synthesis of improved materials are key.

In terms of raw materials, Keda Weilong uses layered lithium manganate, which has high discharge specific capacity and performance and has excellent rate and high-temperature cycle stability. From the perspective of raw material selection, the overall cost performance is higher.

In terms of synthesis methods, HKUST micro dragons use low-temperature calcination semi-wet methods for the synthesis process and composition of conventional lithium manganate materials and improve the positive polar properties of lithium manganate by doping other elements, so that the synthesis temperature is significantly reduced and the time is significantly shortened. However, because of the confidentiality of the process, it can not be described in too much detail.

Previously, there have been media reports that Tesla is preparing to use graphene batteries. It takes only 8 minutes for a charge time and can travel 1,000 kilometers. Wang told the startup state that graphene cannot be used as the main material of the battery and can only be used as a small amount of auxiliary material.

In Wang Meng's view, the best battery material should be high capacity, high discharge voltage, long cycle life, and low price, but the current technical bottleneck mainly lies in the unsatisfactory high-temperature performance.

The team members come from famous domestic and foreign companies such as Guoxuan and Panasonic, and famous universities such as Suzhou University.

The Keda Weilong team is mainly composed of doctoral mentors and doctoral and master's degrees from Jiangnan University and Suzhou University's School of Chemical Engineering. It has its own postdoctoral research workstation and innovation practice base. They have a deep research on advanced batteries for electric vehicles(Li ions, Ni-MH batteries, and Mg-ion secondary batteries, etc.), lithium ion battery materials, Ionic liquids, and nanomaterials. The project members of the team are all master's degree or above. They come from famous lithium-free subsidiaries such as Guoxuan and Panasonic, and famous domestic universities such as Jiangnan University, effectively realizing cooperation in production, study, and research.

At present, Keda Weilong has long-term cooperation with Valance lithium battery Company in the United States. In addition, there are customers such as Taiwan Chong Ge Precision and Zhongshan Kunchen Battery.

At the beginning of 2016, it has raised 40 million yuan and is expected to pass the new three-board listing in 2017.

The page contains the contents of the machine translation.