Power battery ladder utilization? Let's study again
The average battery capacity of an average electric vehicle still has 15 KWh after decay. Third, for the energy storage market, the cost is also a key factor that restricts the commercialization of the industry. Therefore, the demand for low-cost energy storage solutions is also very urgent. If low-cost battery solutions can be obtained through the use of ladders, The development of energy storage industry is also very favorable. The feasibility of battery utilization has been demonstrated more than once. First of all, the power battery is used in groups, and the entire battery may not be used due to the failure of several batteries. This means that in this battery pack, there are still some batteries whose performance is normal. Secondly, many organizations have done a lot of data tests on recovered batteries, and found that many decommissioned power batteries still have acceptable performance in terms of capacity, performance, and cycle life. All of this provides solid evidence for the feasibility of the use of power battery cascades in terms of technology. At home and abroad, the use of ladders is also a state of being in the process of research. Although there are some cases of using ladders, these cases are mostly exemplary. For example, the Beijing Municipal Science and Technology Commission's "Research and demonstration of the life cycle technology of lithium-ion battery systems for electric vehicles" project team uses decommissioned power batteries to perform demonstrations on electric vehicles, electric forklifts, and power substations' DC systems. Compared with traditional lead-acid batteries, battery performance has certain advantages, and it is economical. Japan's 4R Energy Co., Ltd. uses the recovered battery for energy storage and developed home and commercial energy storage products with nominal powers of 12, 24, 48, 72, and 96 kW, respectively. This company was established by a joint venture between Nissan and Sumitomo Electric, so the power battery retired on the Leaf electric car is their main recovery target. U.S. Duke Energy, EnerDel, and Japan’s ITOCHU are also recovering decommissioned batteries with a capacity of less than 80% to promote household energy storage devices. It is important to mention here the research project of lithium battery cascade utilization carried out by the National Renewable Energy Laboratory (NREL), which points out the value evaluation of lithium batteries for vehicles in the recycling process. In general, lithium battery recycling applications for vehicles are based on power systems (including grid-connected and off-grid models), domestic and commercial energy storage systems, and some mobile energy storage. They also point out that secondary batteries must be economical. It must be ensured that it is applied in areas with high economic value and it also needs to be relatively matched with the conditions of battery use. Others such as the California Institute of Technology and the Pacific Northwest National Laboratory have also conducted a lot of research, mainly focusing on the performance of secondary batteries used in different systems, the reliability of batteries, and the cost of batteries, due to space limitations. This will not be repeated here. If a key word is assigned to the utilization of the power battery, it is “researchâ€. At present, the use of ladders is at the “research†stage, mainly based on various models, various experiments, various assumptions, various calculations, and small-scale commercial operations. Or engineering demonstration clues. So what are the problems encountered in the use of battery ladders? Let me say a few major things: First, life is a mystery Although in the power and energy storage markets, the total energy available in the battery (group) life cycle is used to describe the battery life, it has a different meaning. In the power battery, this capacity means the total mileage of the electric vehicle, but in the energy storage market, it means that the battery usage time is 10 years to 15 years. Or 20 years? It can be seen that the biggest difference between energy storage batteries and power batteries is that they require long-term operation. In order to prolong battery life, energy storage battery packs are always guaranteed to operate in the 20%-90% working area, and many foreign energy storage projects This is how the case is done. Even so, there is no guarantee that every energy storage battery can meet the design requirements. During the service period of the secondary power battery, it cannot be guaranteed that it can operate in the 20%-90% discharge interval. According to the actual road conditions, the situation of large rate discharge may occur frequently, coupled with the fashionable fast charging technology. Each item may cause unpredictable damage to the power battery. Although the battery can meet the requirements of the energy storage battery in terms of test performance (such as voltage and impedance) and capacity, the actual life of the second service can reach many years. No one can know. Second, the cost is still a sensitive issue If the energy storage market chooses to retire the power battery, it needs these batteries to have sufficient price advantage. Correspondingly, if you want to further reduce the use cost of lithium batteries through secondary use, then the pricing should include not only the cost of battery recycling and dismantling and sorting, but also the amortization of the cost of initial use of batteries. The battery in the recovery, testing, warehousing, transportation, secondary formation, etc., each link is a cost item, the actual cost of these items may be very different from the cost predicted by the economic model. Without the guarantee of subsidy mechanism, whether the cost of batteries used in the ladder can be accepted by the energy storage market remains to be verified. Third, there are many technical problems The first electric reprinted an article titled " Key Technologies of Ladder Utilization of Power Lithium Batteries ". The article described the key technology of battery ladder utilization is bidirectional DC/DC converter and its numerical control software. In addition, I would like to talk about other issues that may also be encountered during the use of battery cascades. In the recycling of used batteries, the battery must first be failed and disassembled. The so-called failure is to let the battery lose all its electricity and ensure the safety of the dismantling process. For small batteries, failure may be shorting the positive and negative electrodes and releasing the excess power. In industrial production, liquid nitrogen is used to freeze the battery by freezing. The requirements for use of the ladder are just the opposite. The battery is required to be dismantled and is intact. Retired power battery manufacturers are numerous and their models are mixed. Even if the same manufacturer or the same type of battery core comes from different moldings, the grouping method and structure may have a big difference. Therefore, a considerable part of the work may need to be completed manually. The skill level of the workers may affect the yield of the battery recycling process. At the same time, there are security risks in this dismantling process. After completing the battery dismantling, how to evaluate the battery? During the research process, researchers used a variety of advanced instruments and methods to do a lot of testing on decommissioned batteries to evaluate their quality. In the production process, when the power battery leaves the factory, it often goes through the sampling method and completes the strict factory testing (including performance, longevity, thermal stability, safety, etc.). The batteries used in a ladder may be more ambiguous at this stage. First of all, the relatively large amount of batteries, we can not face everything, first of all time and cost is not allowed, followed by all aspects of the test may also cause further damage to the battery itself. If the sample is tested, it is also open to question whether the sampling of this type of battery is statistically significant. When battery detection and screening (grouping based on battery capacity, voltage, self-discharge, internal resistance, etc.) are completed successfully, they face the problem of secondary group formation. The so-called second grouping is the recycling of batteries, once again designed to form Pack to meet customer requirements. This link involves the redesign, processing, and assembly of battery packs. Moreover, because the recycled batteries come from different manufacturers or have different specifications, it means that the Pack design may require multiple design solutions, which will increase design costs and processing costs. After the battery pack was designed, manufactured, and smoothly installed on the site, even more severe tests are coming! These are the batteries that come from the "five lakes and the seas". How do you manage them? At this time, the key technology DC/DC may be effective, but because the internal resistance characteristics, electrochemical characteristics, and thermal characteristics of the managed battery pack are all different, it is even more difficult for BMS development that is a world-class problem. . In addition to longevity and technical issues, there are still many issues that need to be resolved. For example, the battery after-sales problem, the use of battery recycling after the battery recycling processing problems, the use of the battery to share the issue of revenue sharing, is for the electric vehicle users, battery manufacturers battery recycling companies, or a few to allocate ... ... who will be responsible for battery recycling, Who is responsible for the energy storage company or the power battery manufacturer... Battery ladders still have a long way to go to scale-up energy storage, but I think that decentralized, small-scale use of the ladders may be more practical. For example, new energy vehicles in their own homes, batteries that have been eliminated, and slight modifications, become their own “mobile charging treasuresâ€, or as part of small-scale distributed energy storage like the Tesla Energy Wall, may be easier to implement. . LC Two-axis Servo Robot Arm,Servo Robot Arm,Strong Robot Arm Ningbo Rainbow Plastics Machinery Co., Ltd. , https://www.injection-machine.com
It's good to recycle the battery, why do you use it? There are three reasons for this:
First, the cost of lithium batteries occupies a higher proportion in the cost of new energy vehicles. The high cost of lithium batteries is an important factor restricting the development of new energy vehicles. The normal service life of a lithium battery may only be three to five years. By using the ladders to extend the life of the lithium battery, the cost can be reduced.
Second, if the lithium battery that will reach the service life is eliminated directly, it will cause great waste. For example, in 2014, sales of new energy vehicles were 70,000. If this rate grows in the next five years, new energy vehicles will have more than 400,000 vehicles by 2020. If the average single vehicle is equipped with a 20kWh power battery and the average capacity of each vehicle is still 15KWh after decay, even if only half of the vehicle is recovered, the equivalent of 3000MWh battery will be recovered. If these batteries are all in the trash, it's a huge waste. 