Industry experts discuss where the battery technology goes

Wang Binggang (Head of Supervision Expert Team of National “863” Project Energy Saving and New Energy Automobile Major Projects)

Lithium iron phosphate battery is favored for safety

The specific energy and specific price of power batteries are decisive factors for the popularity of pure electric vehicles. Nickel-metal hydride and lead-acid batteries are relatively mature batteries, but the space for energy-saving is relatively small. Lead-acid battery is the basic element of lead, nickel-metal hydride battery is the basic element of nickel, both belong to heavy metals, since the major; and lithium battery is the main element of lithium, itself is very light, can be with a variety of compounds, through the positive The quality of the negative electrode material and the structure of the battery improve the energy storage capacity of the battery, so the lithium battery has a lot of room for development, and the lithium resource reserves in China reach more than 3.8 million tons, ranking second in the world. In a variety of lithium battery technology line, lithium iron phosphate battery for the promotion of electric vehicles to provide the starting conditions, the reason why lithium iron phosphate battery is optimistic because it is the best security, and safety is the basic requirements of the battery Only when safety is guaranteed can the battery's energy storage be discussed. Everything has two sides, and the best safety lithium iron phosphate battery is not the best in terms of performance. It is theoretically difficult to further increase the specific energy of lithium iron phosphate batteries. Many scientists continue to study new power battery materials and structures. The specific energy of lithium iron phosphate batteries is expected to reach more than 150 Wh/kg within 3 to 5 years, and the ratio is 1.5. Below RMB/kg, this is the basic condition for electric vehicles to become popular. However, high specific energy always faces the challenge of safety. Therefore, it is not possible to blindly make large batteries. The larger the battery capacity, the worse the safety. However, we cannot exclude the development of other types of lithium batteries. We say that the safety is based on a few parts per million. We can only say that the safety of other lithium batteries is higher than that of lithium iron phosphate batteries. - The difference in terms of quality, battery safety is also related to the production process, battery management system and many other aspects.

Jian Zijian (Deputy Director, Office of Major Projects for Energy Conservation and New Energy Vehicles, “863” Program, Ministry of Science and Technology)

Lithium batteries and nickel-metal hydride batteries become major investment areas

In 2009 and 2010, China’s investment in batteries will reach 6.018 billion yuan, including local government support, national research grants, corporate investment, and venture capital investment. This is a much bigger investment than before, and its funds are mainly going. The nickel-metal hydride battery and lithium battery industry. By the end of 2010, the annual production capacity of domestic nickel-metal hydride and lithium-ion power batteries will exceed 360 million watt-hours and more than 4 billion watt-hours, respectively, at 30 Kwh per vehicle (approximately 200 kilometers for A-class passenger cars). The battery meter can meet the demand for about 150,000 electric vehicles by the end of 2010. In 2009, the "Ten Cities One Thousand Vehicles" demonstration vehicle was dominated by hybrid buses. In 2010, it was transformed into a purely electric-powered bus, which will increase the demand for vehicle power batteries.

Fang Wang (Senior Engineer, Key Laboratory of Chemical and Physical Power Technology, 18th Institute, China Electronics Technology Group)

Ni-MH battery still has market in 3~5 years

At present, there are four main types of batteries used in electric vehicles: lead-acid batteries, nickel-metal hydride batteries, lithium-ion batteries, and fuel cells. At this stage, the practicality of fuel cells is low, and it is not considered for the time being. The only battery system used in hybrid vehicles is a nickel-hydrogen battery that has been actually verified and commercialized and applied on a large scale. NiMH batteries have been used almost entirely in hybrid vehicles that are manufactured worldwide. Traditional lead-acid batteries, nickel-cadmium batteries, and nickel-metal hydride batteries have relatively mature technologies, but they have major problems as automotive power batteries. At present, more and more automobile manufacturers choose lithium batteries as the power battery for new energy vehicles. For the battle of the power battery line, the industry generally believes that lithium-ion batteries with dominant energy density, helium-ring life, etc. will become the trend of development, while nickel-metal hydride batteries have the advantages of stable performance and mature technology, and will remain in the next 3 to 5 years. Will occupy a considerable market share.

Compared with other types of power batteries, lithium-ion batteries have many advantages: high operating voltage; high specific energy, small size, light weight; long life of 裓-rings.

There are still three major problems in the research and development of vehicle power batteries in China. The first problem is the consistency of manufacturing. There are gaps in manufacturing processes and equipment, and manufacturing standards do not meet consistency requirements. Followed by the screening of the diagnosis-materials, the domestic-produced diagnostics-materials cannot achieve the consistency of different batches. The third issue is intellectual property. Although China has made breakthroughs in the research of lithium iron phosphate batteries, it has patents abroad.

Qian Liangguo (Deputy Secretary General of Power Supply Committee of China Electronic Chamber of Commerce)

Lithium manganate and lithium iron phosphate batteries should be balanced development

At this stage, the industry is controversial about lithium manganate and lithium iron phosphate batteries. I think it should be developed in a balanced manner. Lithium manganate batteries have the advantage of mastering independent intellectual property rights and have higher specific energy, but the lifetime of the yttrium-ring is not as long as lithium iron phosphate batteries. As for the safety problem of the lithium manganese oxide battery, I think there is no meaning in this aspect of the debate. The safety of the lithium manganese battery can be solved by improving the management of the battery system. The advantages of lithium iron phosphate battery is its high safety and long life of the helium-ring, but its low specific energy and relatively poor material consistency. For patent issues, I think the impact on the battery system will not be too great, because Europe and the United States is mastering the patent of lithium iron phosphate battery materials.

What kind of lithium battery is used? It still has to be decided according to the requirements of the vehicle. For example, some models require a long-life battery, you can choose lithium iron phosphate, and some models require a light, high energy density battery, you can choose lithium manganate. Lithium batteries replace nickel-metal hydride batteries in the next few years is an inevitable trend. From the price point of view, the price of lithium batteries is declining, and the price of nickel-metal hydride batteries has gradually increased. Moreover, the safety of nickel-metal hydride batteries is much lower than that of lithium batteries, which is prone to thermal runaway and causes burning. Therefore, in June 2006, Toyota announced that the Prius will use a lithium battery for four years. However, the development of high-power lithium batteries has only just begun. Only when the power density increases by 20 to 30 times can the nickel-hydrogen batteries be replaced.