At the Energy Storage International Summit and Exhibition 2018 (ESIE) held in Beijing not long ago, Prince Dong of the North China Vehicle Research Institute and the National 863 Power Battery Test Center made "How to Make the Energy Storage Industry an Environmentally Friendly Industry?" Keynote speech.
Prince Dong pointed out that China is a big energy importer, with more than 60% of primary energy reliant on imports, and strategic energy security has great risks. At present, China’s power generation structure is unreasonable, and the proportion of thermal power is too large. “Improvement of power generation structure, active development of new energy, and clean green energy power generation are undoubtedly imperative.” Electrochemical energy storage has fast response, flexible configuration, precise control, and environment The relative friendliness and other characteristics are considered as the "best partners" for new energy generation.
Prince Dong said that it can be foreseen that the mainstream type of batteries for the energy storage market in the future will be large-capacity batteries with a capacity of more than 100 Ah in square hard cases and square flexible packages. Lithium iron phosphate with silicon carbon anode is considered by the industry to be the mainstream material system for a period of time in the future. The product adopts a flat roll and lamination process and is characterized by safety, long life, and low cost.
As far as the current technology is concerned, lithium-ion batteries are an ideal energy storage method, and they have clear advantages over other energy storage technologies such as lead-acid batteries. However, whether it is a disposable lithium battery or a secondary lithium battery, all contain a variety of metals and electrolytes, organic solvents and by-products generated by the battery recycling process, will cause environmental pollution. Resolving the issue of battery recycling as soon as possible has become a major task for the entire society.
The concept of battery cascade utilization in China has long been accepted. Although a complete application model has not yet been formed, its application prospects are still high hopes. Prince Dong believes that through the use of the lithium-ion battery system throughout the life cycle of the ladder to break through the key technologies of lithium battery recycling of waste materials, and establish a multi-level closed power battery system core components and key materials recycling system and recycling Economic model.
The goal of the power battery recycling economy is to achieve a low-cost step-by-step utilization of power batteries, to lengthen the application chain, to achieve energy-efficient and environmentally-friendly material decomposition and classification, and to achieve harmless recycling and material regeneration. The multi-level utilization and recovery of power batteries is of utmost importance. Prince Dong pointed out that “not only for environmental protection, but also the use of profitable business models will affect the standard, performance, structure, production process, and material system of power batteries worldwide. ”
Prince Dong pointed out that whether the power battery has the value of recycling, first of all, the economic account should be calculated, and the benefits of multi-level battery utilization should be evaluated in advance. Because of the practical application, the recovery value of many materials is relatively low, especially the implementation of lightweight technology, resulting in the use of non-metallic materials for many companies' battery box materials, and their value is even lower. For lithium iron phosphate and other batteries, the positive electrode material recovery value is small, according to the traditional recycling process will certainly lose money. Wang Zidong said that after the "economic account" is calculated, the next step in the process can be considered.
Prince Dong believes that the use of low-cost power battery cycles is difficult. The problem lies mainly in the structure of the battery products and the production process. Some companies use laser welding to increase the reliability of the battery pack, which greatly increases the difficulty of battery utilization. In addition, since different models have different battery pack designs, it is difficult to dismantle the power battery with a complete assembly line after decommissioning, resulting in time-consuming and laborious dismantling. He said that even Tesla, the world leader in the field of electric vehicles, is also difficult to dismantle its power battery system.
Prince Dong emphasized that the integrated design of the power battery is very important in order to achieve low-cost step utilization in the energy storage field. At the time of design, it is necessary to implement the concept of “battery structure should be easily connected and reconnected, facilitate system adjustment and maintenance, and be hot-swappable”. At the same time, it needs to be clear: the physical decomposition efficiency of the non-crushing method of the power battery must be far Higher than production efficiency. Therefore, the use of non-crushing methods is a more economical method. At present, most recycling companies in society adopt smashing methods, which undoubtedly increases the cost of recycling.
He pointed out that the cost and profitability issues are the major obstacles to battery recycling. The high cost of recycling processes and the low recycling value have deterred many companies and capital. Therefore, "we must develop a low-energy, environmentally friendly material decomposition method." Prince Dong emphasized.
In the end, how to really solve the economic problems of power battery recycling? Wang Zidong believes that “by establishing a highly efficient and reliable lithium-ion battery system multi-stage utilization and recovery cycle system, we can reasonably allocate the cost of using lithium-ion batteries throughout the life cycle, and directly reduce the lithium-ion power battery system over the entire life cycle. The cost of application in the electric vehicle industry is currently the most appropriate and effective solution."