Talking about the disposal of used power batteries?

With the rapid development of the new energy automotive industry in China, the power battery market will usher in a huge increase. At the same time, the problem of power battery recycling and reuse will become more and more prominent. In general, the power cell capacity is less than 80 % of the initial capacity and the power cell life is considered to be over and can no longer be used in new energy vehicles. Judging from the current technology, the cycle life of a power battery pack is about 1000-1500 times, equivalent to a service life of about 5 years. With the large-scale promotion of electric vehicles, the number of power batteries will become more and more scrap. According to the forecast of the China Automotive Technology Research Center, by 2020, the total number of power batteries of electric vehicles in China will reach 120,000 to 170,000 tons. Therefore, China urgently needs to build a power battery cascade recycling industry chain.

The status quo of power battery echelon recovery in China

1. Policy

In the "Development Plan for Energy Conservation and New Energy Vehicle Industry(2012-2020)", which was promulgated in July 2012, China clearly put forward "the formulation of power utilization management measures and the establishment of a power battery cascade utilization and recovery management system. Clarify the responsibilities, rights, and obligations of the parties concerned. We will guide power battery manufacturers to strengthen the recycling of used batteries and encourage the development of specialized battery recycling enterprises. However, this plan does not specify the authority and responsibility in the recycling process.

In 2015, the Ministry of Finance and other four ministries and commissions jointly issued the Circular on Financial Support Policies for the Promotion and Application of New Energy Vehicles for the Period of 2016-2020.

In order to encourage manufacturers to recycle power batteries, many local governments are also actively exploring. Shanghai has issued a policy that the government will subsidize 1,000 yuan/set of power batteries for the recycling of motor vehicles; Shenzhen has established a power battery utilization and recycling system: each car manufacturer has taken out 600 yuan and the government has taken out 300 yuan to recycle power batteries and initially establish a battery recycling mechanism.

2. The current state of development

At present, enterprises and institutions including the National Grid, local governments, and battery companies have all carried out research on power battery echelon recovery and made certain progress, but it still belongs to the exploration stage and has not yet formed an industrial chain.

China National Network Zhejiang Company explores the ladder recovery of power batteries on electric bicycles. In 2013, the State Network Zhejiang Electric Power Company completed the "Power Battery Electric Bicycle Echelon Utilization Technology Plan", which reorganized the core of the end-of-life battery of electric vehicles and transformed it into a power source for 48-volt electric bicycles to achieve energy conservation and emission reduction.

China National Network Beijing Company will use the battery ladder and fast charge combination. In March 2014, the Beijing Academy of Electronic Technology of the State Network launched a project entitled "Research and Demonstration on the Use Technology of Electric Vehicle Power Battery Echelon", which combines the use of retractable battery steps with DC fast charging stations, and at the same time use a 100-kilowatt-class energy storage system. Access, dynamically adjust DC load in charging stations, Stabilizing the voltage node, reducing the peak and valley difference of the charging station, and improving the comprehensive operating efficiency of the charging station.

The State Network Henan Company has built a micro-grid system and created a standardized process for power cell sorting, evaluation, and distribution. The State Network Henan Company, together with Nanrui Group and battery manufacturing enterprises, has completed a demonstration project for retired battery energy storage through comprehensive research and practice in basic theory, application technology, and demonstration and promotion. The country has taken the lead in building a set of standardized processes for the use of retired power batteries from sorting, restructuring to store energy. The project is located at the Jianshan Zhen-type transmission line test base in Zhengzhou City. It is the first truly hybrid microgrid system based on decommissioned power cells in China. After the successful transfer, it has been operating continuously for 1 year and has a cumulative power supply of more than 45,000 kilowatt-hours. The current system is in good condition. In addition, China National Network Henan Electric Power also led the establishment of a technology platform for the separation and assessment of retired batteries, which has achieved safety assessment, cycle life testing, and sorting and grading of retired batteries; In view of the inconsistent performance of retired batteries, the technical specification of the battery allocation group was formulated, and an efficient and reliable battery management system was developed, which improved the secondary cycle life of batteries. A retired battery energy storage system with different voltage and capacity levels has been developed, which has promoted the demonstration application of retired battery energy storage systems in small energy storage fields such as electric motorcycles.

The Beijing Science and Technology Commission has achieved better economic results through the modification of ground cars and substations. The Beijing Municipal Science and Technology Commission's "Study and Demonstration of Lithium-ion Battery System Full Life Cycle Utilization Technology" project group uses decommissioned power cells to perform retrofit demonstrations on electric field vehicles, electric forklifts and power substation DC systems. Compared with the traditional lead-acid batteries, the performance of the recycled batteries has certain advantages and is economical.

Cascade recovery problems

Echelon utilization is more capable of exploiting the more value of power cells, reducing the overall cost of power cells, and maximizing the benefits of the circular economy. However, terraced utilization still faces many difficulties and challenges. If it can not be effectively solved, it is difficult to achieve industrialization.

1. Battery Matching Problem

The battery routes, the type of battery specifications and the requirements for the evaluation of batteries vary from one company to another in China, resulting in too many models of batteries, and different types of battery voltage and charging and placing platforms are all different. Therefore, it will cause great difficulties in the battery sorting process. Due to the large scale of energy storage batteries, they often use 100 kilowatts or even megawatts as units, so the problem of battery matching in the field of energy storage batteries is particularly prominent.

2. Matching with energy storage items

Energy storage batteries belong to the engineering properties of batteries, the construction time and space are relatively concentrated, with a clear time limit. Power batteries belong to the application of product attributes, and battery elimination occurs anytime, anywhere, and does not match the engineering properties of energy storage batteries. If there are energy storage items, then go to the market to recover batteries, the time limit can not be guaranteed; If you store the batteries that are usually recovered, it may increase the cost of recovering the batteries, and the performance of the batteries may also change during the storage process.

3. Secondary cost of batteries

In the process of battery echelon utilization, its recovery, dismantling, sorting, transportation, warehousing, and secondary formation require costs for each step. In particular, during the battery dismantling process, due to different factory battery structures, module connections, and process technologies. Different, Automation equipment is difficult to complete, requiring a large number of manual operations, low efficiency, and due to factors such as damage during the dismantling process, there is uncertainty in cost. How to effectively reduce this part of the cost and improve efficiency will become a power cell. The key factors for effective echelon utilization.

4. Safety issues

The battery itself is an energy carrier, and even after the discharge is completed, there is still some energy residue. In the battery dismantling process, due to the existence of a large number of manual operations, the operation specification is difficult to guarantee. If there is an improper operation, it is prone to short-circuit, leakage of liquid and other problems, which in turn causes safety accidents such as fire explosions.

summary

It is expected that in the next 4-8 years, the new energy vehicle batteries to be promoted at this stage will gradually be scrapped. Judging from the current development of power battery recycling, China is still in the initial stage and is far from industrialization. The government and enterprises urgently need to step up their layout. Avoid a passive situation in the future.

The page contains the contents of the machine translation.