Can the power battery "step utilization" improve energy efficiency?

As of 2017, China has promoted more than 1.8 million new energy vehicles, and the energy density of power batteries has tripled compared with 2012. The price per kWh has dropped by more than 70%. Data show that in 2020, China's domestic automotive power battery recycling capacity is expected to reach 25.7 tons, and in 2022 this data will reach 42.2 tons.

With the rapid development of new energy vehicles, China's power battery decommissioning will gradually become a scale. After the vehicle power battery is decommissioned, it is necessary to consider its use and recycling. Experts from the industry have mentioned the problem of recycling and utilization of power batteries. Among them, “step utilization” has become a high-frequency vocabulary.

So, how is the power battery cascade utilization carried out? Where is the decommissioned power battery going?

Liu Yanlong, secretary general of the China Chemical and Physical Power Industry Association, said that after the power battery is decommissioned from the electric vehicle, 80% of the capacity can be utilized. Therefore, it is necessary to attach great importance to the utilization of the power battery ladder.

Liu Yanlong stressed that to carry out the use of the ladder, we must first understand the quality and safety performance of the decommissioned battery. Battery companies should establish a big data tracking system platform and evaluation methods for battery testing. Big data should include production data for electric cell research and development, battery pack R&D and production data, battery pack vehicle operation monitoring data, etc., and conduct health evaluation of decommissioned batteries through big data to determine whether the battery can enter the ladder utilization market.

In addition, it is necessary to pay attention to the standardization of battery cells and battery packs. It is possible to use as few standard cells as possible within an enterprise, which can improve the level of production automation to reduce costs and improve product consistency, and is convenient for future use. Dismantling and reorganization, therefore, in the power battery design phase, it is necessary to prepare for subsequent step utilization and dismantling recovery.

Of course, not all power batteries are suitable for use. Wu Hui, research director of the Ivey Institute of Economics, pointed out that the ternary power battery contains lithium, cobalt, nickel, manganese, copper, aluminum, graphite, separator and other materials by disassembling rare metals such as nickel, cobalt and manganese. It can realize economic benefits of about 4.29 yuan per ton, thus achieving economic feasibility. However, if the lithium iron phosphate battery can only achieve an economic benefit of about 0.93 yuan per ton by scrapping and dismantling, it is difficult to cover its recycling cost. lithium iron phosphate power battery is more suitable for the use of the ladder.

Then, where is the battery used after the ladder is used?” After recycling from the retirement battery, we apply it to the energy storage field. After the ladder is used, the battery will eventually be taken back for dismantling, recycling, and physical sorting using automation technology. Raw materials.” Zhang Chunxi, director of the second business unit of BYD Battery Group, pointed out that taking BYD as an example, the cathode material lithium iron phosphate, ternary materials and our anode materials were recycled at this stage. The feasibility study has been completed and a recycling production line of a certain scale has been completed.

The operating mode of power battery ladder utilization is an issue that is constantly being explored in the industry. At the conference, a person in charge of a power battery company said that building a storage power station or continuing to use it on a low-speed electric vehicle may be a feasible direction for the utilization of power battery ladders. "At present, whether it is a large energy storage system or a small energy storage system, in general, the use of power battery ladders will be more used in energy storage," he said.

It is understood that starting in 2015, BYD has already cooperated with other enterprises to build energy storage power stations. “In Wuxi, for example, we combined new energy vehicle charging piles to create a storage power station-type charging system. Now the charging stations are directly “hanged” on the grid, so we all charge higher during the day and charge. The cost will be higher. Our charging base station can reduce the charging price by “shaping the peak and filling the valley.” Zhang Chunxi stressed that in the future, BYD will cooperate and cooperate in the field of power battery recycling industry, Hand in and hand with recycling enterprises to do a good job in power battery recycling.

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