How much do you know about power battery cascade utilization?

Under the background of green environmental protection, new energy vehicles have entered a period of rapid development, especially since last year, the output and possession of new energy vehicles have risen sharply. Along with this, the use of power battery cascades for electric vehicles has gradually become a hot spot in the industry.

In order to guide and promote the use of power battery cascades, policies are continuously introduced at the national policy level. In 2015, the “Regulations on the Standards of Automotive Power Battery Industry” issued by the Ministry of Industry and Information Technology put forward requirements for the recycling and reuse of used power batteries. The Ministry of Finance and other four ministries jointly issued the “Financial Support Policy for the Promotion and Application of New Energy Vehicles in 2016-2020 Notice". At the beginning of 2016, the Ministry of Industry and Information Technology and other five ministries jointly issued and issued the "Electric Vehicle Power Battery Recycling Technology Policy (2015 Edition)", which aims to promote the orderly recycling of power batteries and promote resource recycling.

Expanding power battery cascade use of business opportunities

In 2015, China's total production of new energy vehicles totaled 379,000 units, a four-fold increase over the same period last year. The reporter learned from the China Chemical and Physical Power Industry Association that the domestic power battery production in 2015 was about 16GWh. It is expected that the new investment capacity will be 20GWh this year and next, and will reach 32GWh by the end of 2016. The booming market has also attracted domestic and international battery manufacturers to expand their production capacity.

With the explosive growth of new energy vehicles, there will undoubtedly be a large number of decommissioned power batteries after 4-5 years. According to the prediction of China Automotive Technology and Research Center, by 2020, the cumulative scrap of power batteries for electric vehicles in China will reach a scale of 120,000-170,000 tons. If these decommissioned batteries are used directly for resource recovery, it will inevitably lead to waste. The most effective way to maximize its function is to use it in cascades and then recycle it as a resource.

As Yusheng Yang, an academician of the Chinese Academy of Engineering, said: "There are advanced manufacturing technologies for these scrapped power batteries. Even if they still maintain high safety and electrical performance after being scrapped, it is necessary to use the cascade utilization method to maximize the utilization of waste power batteries. ”

It is understood that at present, there are many cases in which the used power batteries have been tested and reorganized in China and applied to the field of energy storage. Previously, Professor Lu, a doctoral tutor at the New Energy Materials and Technology Laboratory of Peking University, told reporters that hundreds of electric buses that were put into operation in the 2008 Olympic Games are now used for energy storage in wind power and photovoltaics after three year of operation.

During the interview, many interviewees believed that considering the strong development trend of electric vehicles in the future, they will also bring the blue ocean of power battery cascade utilization.

"I am full of hope for the market for power battery cascade utilization. In the future, I will see more decommissioned power batteries for energy storage." Shicheng Wang, chairman of Beijing Suoying Electric Technology Co., Ltd., said in an interview.

Scrutinize cascade use of technical problems

The power battery has reached the end of its life according to national standards. When it is removed from the new energy vehicle, it has considerable capacity and a relatively wide space for use. The use of decommissioned power batteries in the field of energy storage is a good choice, both economically and environmentally friendly.

However, retired batteries are not as easy to use as they are supposed to be, and there are some technical obstacles. When the cascade is used, the consistency of the battery is very different from that of the new battery, which poses a great obstacle to the use of the group. At the same time, when the battery capacity, voltage, internal resistance, etc. are used in the cascade, it will form a cliff-type fall with a small number of cycles, which is extremely difficult for later use.

An authoritative expert in the field of energy storage told reporters that there are support and opposition to the use of power battery cascades in the industry. “The negative point is that the idea is good but not very feasible.”

In his view, there is a difference between the decommissioned batteries, especially the uniformity, just like the barrel theory, the shortest board determines the actual capacity of the barrel, and the worst battery determines the performance of the entire energy storage system. “If you use it for large-scale energy storage at the grid level, there is a high probability of problems. However, in household energy storage and small-scale energy storage, it is okay.”

"Retired battery recycling in the smaller family storage battery, UPS (uninterruptible power system) is feasible."Chinese academy of sciences, institute of electrical energy storage technologies Chen Yong led the team of her said to the reporter, "but for large energy storage power station, want to consider circulating sex, security, among them there are nonlinear changes, can increase the probability of an accident, it will cause security risk, and at the same time management costs will be high. Power battery cascade utilization, however, is not the ultimate solution. We also need to actively develop a new type of environmentally friendly power battery recycling easily."

Explore the retired battery recycling

In order to promote the cascade utilization of power battery, in addition to the national policy level to encourage support, many local governments are actively exploring.

Policies, such as Shanghai auto enterprises power battery recycling government subsidy 1000 Yuan/set; Shenzhen set up power battery using and recycling system, each car manufacturer sold out 600Yuan, the government took out 300Yuan, used for recovery of power battery, preliminary set up the system of battery recycling.

It is reported that at present, enterprises including state power grids, local governments, and battery companies have carried out research on power battery cascade recycling. For example, the State Grid Henan Power Company built the microgrid system in 2013, and created a set of standardized processes for power battery sorting, evaluation, and matching.

According to public information, the project is located in Zhengzhou City's Jianshan True Transmission Line Test Base. It is the first hybrid microgrid system based on decommissioned power batteries in China. The system is in good condition. In addition, State Grid Henan Power Company also led the establishment of a decommissioning battery sorting evaluation technology platform to achieve safety assessment, cycle life testing and sorting grading of decommissioned batteries.

“The key to the use of retired battery cascades is the reorganization of batteries. Last year, we used some of the demonstration projects in Fangshan and Yanqing in Beijing, and the overall performance is OK.” Kong Qixiang, chief engineer of Beizheng Microgrid Technology Co., Ltd. told reporters, “At the time of purchase, the manufacturer has tested it to ensure the consistency of the battery after reorganization."

The reporter learned from Beijing Suoying Electric Technology Co., Ltd. that it started to store energy in 2009 and participated in the State Grid Henan Project, Zhangbei Fengguang Storage and Transportation Project and several FM and microgrid projects. "We started from energy storage, thanks to years of technology accumulation, in terms of battery cascade utilization, whether it is system life or battery consistency and cost, we have our own balance." Wang Shicheng said, "We have our own charge and discharge evaluation system, test equipment, etc., through the detection equipment, reorganize the battery to form the system energy storage. Our cascade utilization should be mainly used in the park and building projects, and the role is to use it.

According to Shicheng Wang, the current capacity of the company's battery cascade utilization is about several million megawatt hours. "It mainly depends on the scale of the decommissioned battery." "The new energy vehicle market is booming in the past two years. In the next few years, the decommissioned battery is in energy storage. The field application market will also increase." Qixiang Kong believes.

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