Trends in power cells

As the core component of new energy vehicles and the key to the commercialization of the industry, the development of the power battery industry has been concerned by all walks of life. In recent years, under the control of national policies, major vehicle companies have made major adjustments to new energy models and supply chains, which has led to a new round of development of the battery industry as a whole. In the six batches of announcements announced in the first half of the year, up to 85 batteries were involved.

It is worth mentioning that soft packaging batteries have shown strong growth in this process. According to statistics from relevant research institutions, the output of Square, cylindrical, and soft-pack lithium batteries in China in 2015 was 17 GWh, 10.1 GWh, and 19.8 GWh, respectively, accounting for 36.4 %, 21.5 %, and 42.3 %, respectively. The ratio of soft-pack batteries has exceeded that of square and cylindrical batteries. In the first three quarters of 2016, due to the fluctuations in the market for new energy vehicles, the output of square and cylindrical batteries has declined to varying degrees. Only the output of soft-pack batteries has increased in the first three quarters of 2016, and domestic soft-pack batteries have reached 13Wh in the first three quarters. Among them, The third quarter saw an increase of 20 per cent over the third quarter.

At present, Beiqi, Chang 'an, Dongfeng and other domestic high-end new energy passenger car products, began to use soft power batteries. LG, AESC and other foreign power battery companies have also started mass production of soft-pack batteries.

"In the future, soft-pack batteries will be widely used in passenger cars and become the main force in the new energy car market. "Beijing Guoneng Battery Technology Co., Ltd.(hereinafter referred to as Guoneng Battery) executive deputy general manager Zhangjingshu said.

Data show that at present, there are three main forms of lithium battery packaging, namely cylindrical, Square and soft package.

The production process of cylindrical lithium cell is mature, the cost is low, the product yield and the consistency of the battery pack are high, the heat dissipation performance is better than that of the square cell, and it is convenient for a variety of forms and is suitable for the full layout of the space design of electric vehicles. However, due to the use of steel shells or aluminum shells, the self-weight is higher and the specific energy is relatively low.

Square hard shell battery cases are mostly aluminum alloy, stainless steel and other materials, the internal use of winding or folding technology. Since square lithium batteries can be customized according to the size of the product, there are thousands of models on the market, which makes it difficult to unify the process.

In contrast, the packaging material and structure of the soft-pack battery give it a series of advantages. For example, the weight is light, and the weight of the soft-pack battery is 40 % lighter than the same capacity of the steel shell lithium battery, and 20 % lighter than the aluminum shell lithium battery; The internal resistance is small, and the internal resistance of the soft pack battery is smaller than that of the lithium battery, which can greatly reduce the battery's self-consumption; Good circulation performance, longer cycle life; Flexible design, variable shape and arbitrary shape, can be customized according to the needs of customers, the development of new core model.

Judging from the market development trends in recent years, the proportion of soft-pack batteries has become increasingly high. Some experts predict that the market share of soft-pack batteries in the future is expected to exceed 50 %.

According to a research report released by Haitong Securities, soft-pack batteries have great room for development in the power field in the future. The report pointed out that soft-pack batteries are 20 % lighter than the current mainstream technology route, have a higher energy density, have better safety, and have higher cycles; The share of soft-pack batteries in the overall market of lithium batteries in China is about 35 %. It has proved its superiority in the 3C field, but the share of power batteries in this sub-link is estimated to be less than 10 %. The domestic power soft pack battery is still in the initial stage, the future has great development space.

The most important thing is that the security performance of soft-pack batteries is better.

"Because it is a soft packaging, it is a hot sealing method through the PP film, so the internal pressure is relatively low. In the other two(hard) packaging cases where the blast valve can not be fully opened, such an explosion may occur. Therefore, the safety performance of soft packaging is slightly better. "Aiqun, deputy general manager of a domestic power system limited company, said.

At present, many battery companies have increased and accelerated the development and production of soft-pack batteries. Among them, the National Energy battery is the leader. In the new car catalogue in the first half of the year, the number of vehicles supporting the National energy battery entered the top three, and it has already been used for passenger cars such as Ankai, Dongfeng Automobile, Dongfeng Brigade, Yaxing, Nanjing Jinlong, Zhuhai Yinlong, and Beiqi Yinxiang. The car company has completed supporting and batch supply. At present, Guoneng Battery has built eight major production bases in Beijing, Henan Zhongmu, Zhejiang Haining and Hubei Xiangyang. Production capacity will reach 11GWh by the end of this year, and it is expected to become the world's largest manufacturer of soft package electric batteries. It is expected that production capacity will reach 25GWh by 2020.

Guoneng Battery Chairman Guowei said that Guoneng Battery makes the strategic decision of starting power soft-pack batteries based on the judgment of technology trends.

"China's new energy automotive industry is constantly developing and upgrading. As the most core component, the upgrading and change of power cell technology must be faster. The development direction of the entire industry must be high performance and high energy density. In the end, the market proved us right. " said Guowei.

According to him, the energy density of the battery pack produced by the National Energy Cell has reached 125wh/kg in 2016, and the energy density of the three-way mass production has reached 200wh/kg. It is expected that by the end of 2017, the monomer density of NNEU lithium iron phosphate batteries will be 180 Wh / kg, and the ternary product will exceed 240 Wh / kg.

Some experts pointed out that the current competition in the power battery industry is fundamentally a technology competition. A technical team with high-level researchers as the core and research direction covering the key areas of battery technology is the guarantee for the National battery to achieve a leading position.

It is understood that at present, the core personnel of the Guoneng Battery Technology Team are all high-end talents in the industry: Wucongxiao, deputy general manager, is the leading figure in the new energy field of the "Thousand People Plan" of the Central Organization Department, and Ph.D. in Electrochemistry of the Chinese Academy of Sciences; Ma Juntong, the technical director, is an expert in the "Thousand People Plan" of the Central Organization Department. He has presided over major special projects such as the National 863 and has more than a dozen major inventions of electric vehicles. In addition, Guo Neng's chief power battery scientist Lidecheng, from the Sony power battery Department, has long been engaged in energy material research and development; Chief Advanced Battery Kexuejiawenzheze used to be the technical head of NEC Energy Company and developed products for Samsung and Hitachi.

At present, Guoneng Battery has established the Beijing R&D headquarters and Wuxi R&D base, and the Shanghai R&D branch will be officially opened at the end of the year. The company already has perfect research and development system and perfect experimental conditions. It has high-tech research center, battery simulation platform, battery management system and battery development experimental platform.

However, there are also voices that believe that whether it is cylindrical, Square or soft-pack batteries, the reason why they can develop rapidly is because they have been well used in their respective fields of application. The power battery industry is accelerating from the introduction phase to the rapid development phase under the policy and market two-wheel drive. In the choice of technical route, the situation of Square, soft package and cylinder in China will be maintained for a long time. Their market share also depends on the specific development of the downstream market.

The page contains the contents of the machine translation.