Power battery energy storage before and after the application of scrap

The energy storage application of lithium batteries in electric vehicles can be divided into two parts according to the sequence of use. The early part refers to the application before the scrapping of lithium batteries in electric vehicles, and the later part refers to the energy storage application after the scrapping of lithium batteries in electric vehicles, which is the cascade utilization advocated at present.

In terms of energy storage, electric cars have naturally become part of the energy storage application since the beginning of its use. The use of electric cars can be calculated from the birth of the car, it has been more than 100 years, because of the battery, the distance can not meet the needs of people, can not compete with fuel cars. Until recent years the lithium battery is applied to the electric car, back to the car on the market to make electric cars, tesla electric cars were optimized, using high-performance 18650 batteries for one time charge trip mileage reached 500 kilometers, the acceleration of the electric car is superior performance and comfortable driving experience, let people to enhance the confidence in electric cars. With the rapid growth of production and sales of electric vehicles, the cascade application and scrap disposal of lithium batteries in electric vehicles have become an urgent problem to be solved.

Energy storage application is to point to electric energy, water energy, air energy, power energy commonly wait for energy to save first, take out again at appropriate time undertake applying. Electric cars, as consumers of electricity, are different from other power supplies. A lamp is directly converted into light when it is used for electricity; an electric motor is directly converted into power when it is used for electricity; an electric furnace is directly converted into heat when it is used for electricity; and an air conditioner is used to convert electricity into cool air. Electric cars store their electricity in lithium batteries and convert it into power when they are on the road. This is what we call the energy storage application of electric vehicles. It is an ideal way to charge the battery at night when the power grid is at a low ebb and drive it on the road during the day. In many cases, the battery will be charged at peak hours and then driven on the road. When many types of electric vehicles are recharged and then driven, serious uncertainties will occur in the charging time. This is a far cry from the energy storage applications expected by the grid. We are vigorously promoting the application of energy storage of chemical batteries, most of which refer to charging when the power grid is at a low point, reverse feeding the power to the grid at a high point, or directly feeding the power to the user. Many countries in the world have made great efforts to develop chemical energy storage technology for this purpose.

The rapid development of electric vehicles has strongly promoted the development of lithium battery industry. The energy density of lithium battery has been greatly improved compared with that in 2010. The driving range of one charge is also increasing year by year. Now a lot of new energy automobile enterprises commitment to the consumers of the service life of the battery and the quality assurance is most 10 years time, but if considering the use environment such as the comprehensive situation, power battery life expectancy will be lower than 10 years, the normal use of electric cars, lithium battery life is commonly according to 80% of the nominal capacity as a standard, less than the number of the use of lithium batteries would not be in the car. In actual use, lithium batteries with a nominal capacity of less than 80% can be used for many cycles normally, which enables lithium batteries in electric vehicles to play a certain role in energy storage applications after being scrapped.

In theory, after the lithium battery of electric vehicles is scrapped, 80% of its capacity lower than the nominal capacity can be reused or used in cascade. They can also be used in energy storage projects or related power supply base stations, street lamps and low-speed electric vehicles according to the battery capacity, and finally enter the recycling system. Actually energy storage density of monomer battery project requirements, though less power battery is so high, but a storage battery energy storage projects of larger scale, usually to hundred kw even megawatts, and a new energy car battery capacity is generally 10 to 50 KWH, the largest is 100 KWH, if you want to be used for power battery energy storage, there is no doubt that need a lot of battery pack, which will make the whole battery storage block facing consistency management difficulties, which will affect the whole piece of the use of the energy storage battery project. What's more, in terms of the current situation of lithium battery industry, due to the different battery routes, battery specifications and battery evaluation requirements of different car companies in China, there are too many battery models, which leads to excessively dispersed output and greater difficulty in cascade utilization.

Although there are various problems and difficulties in the later use of lithium batteries in electric vehicles, the recycling and reuse of lithium batteries in electric vehicles has become a top priority. According to the 13th five-year plan, China will produce and sell 5 million new energy vehicles by 2020. According to the prediction of China automotive technology research center, by 2020, the accumulative scrap volume of electric vehicle power batteries in China will reach 120,000 to 170,000 tons. We should establish an effective recycling and recycling mechanism and never allow the discarded lithium batteries to cause greater harm to our environment.

Recycling and recycling of lithium batteries should be a greater responsibility for battery manufacturers. Although battery manufacturers are busy expanding capacity, they should also focus on recycling and develop environmentally friendly ways to decompose and reuse lithium batteries. Because the technology is not in place, the current whole new energy battery recycling business chain has not been improved, the whole industry has not formed a closed loop. Now lead-acid batteries can be recycled in car repair places and garbage collection places. Why? That's because it's so easy to make a business out of recycling lead-acid -- take a screwdriver, pry open a spent battery, dump the acid, take the most valuable lead sheet and resell it for money.

Why can't lithium batteries be recycled? Relevant professionals believe that the recycling process of lithium battery is too complicated, and it is very difficult to directly recover the positive electrode material, negative electrode material, electrolyte, diaphragm and other high value-added intermediate products from the waste lithium battery. In addition, different manufacturers of lithium battery materials and formulas are different, to complete the recycling is not easy. Therefore, it makes sense for battery manufacturers to recycle scrapped lithium batteries. Tesla has a set of disposal methods for recycling its own scrapped lithium batteries, which does not involve high-energy smelting and can reuse more than 70% of materials, leaving only some carbon dioxide, water and dust, and no other pollutants. Such a solution is worth learning from.

There are many difficulties in energy storage application and recycling and reuse in the later stage of lithium battery for electric vehicles. Can we find a way to apply energy storage in the early stage of lithium battery for electric vehicles and apply energy storage in the later stage of lithium battery for electric vehicles to the early stage? With the generation of lithium batteries that can be rapidly charged with graphene technology and have a higher cycle life, we should fully explore the potential energy storage application of lithium batteries. Although according to certain standards, 80% lower than the nominal capacity lithium battery capacity will not be able to use in the car, but with the experimental results show that lithium batteries from nominal capacity decreased to 80%, if the number of cycle can reach 1000 times, from 80% of nominal capacity to 60% of the nominal capacity, the cycle number will achieve even more than 1000 times. Therefore, it is feasible to reduce the scrap standard and extend the service time, which can improve the service efficiency of electric vehicles. Of course, it is possible that the cycle life of some lithium batteries will drop sharply after the nominal capacity is less than 80%, which requires lithium battery manufacturers to indicate the value when the cycle life of the battery drops from the nominal capacity to 60% in the operating instructions, so as to provide a basis for the cascade application of lithium batteries.

Electric car manufacturers should specify extended using the corresponding warranty policy support extended use their electric cars, take not meet the requirements of the energy storage lithium battery energy storage power station for pilot application, without the need for, if the lithium battery to dismantle the coach as some small energy storage applications, can also be considered. Today's electric cars, which have a range of more than 300km on a single charge, have half the battery capacity and can be used for short distances. For consumers, scrap is not valuable, owners should have the right to use and disposal, we should support and understand this.

Electric vehicle is a portable energy storage power station. With the transformation of two-way power supply of power grid and the establishment of energy Internet, this mobile power station can not only store power from the power grid for its own use on the road, but also supply power to the power grid and users when needed. In this way, electric vehicles are distributed on the power grid as many distributed energy storage power stations. Charging and power supply of different electric vehicles can reduce the power supply peak of the power grid and play an important role in the safe operation of the power grid. In this way, the owners can obtain certain benefits and reduce the expense of electric vehicles by appropriately reducing the scrap standard of lithium batteries in electric vehicles and extending the energy storage and utilization time of lithium batteries in electric vehicles. Doing so will become the electric car charging pile important device connected to the grid and energy of the Internet, will probably be all can parking reserved and charging pile installation, to meet and promote the electric car be used widely in our country, better play to the role of the electric car lithium-ion battery energy storage power station, and ensure the safety of power grid. In the context of the elimination of local subsidies for electric vehicles and the decline of state subsidies, such a more environmentally friendly, more economical and more reasonable use of electric vehicles is worth doing.

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