Analysis of lithium battery recycling methods

Regarding the decommissioned power lithium-ion battery, there are currently two feasible solutions: one is cascade utilization, which is to use the decommissioned power lithium battery in other areas such as energy storage as a carrier of electric energy, so as to give full play to the remaining value; The second is dismantling and recycling, which is about discharging and disassembling the decommissioned batteries to extract raw materials for recycling. At present, only lithium iron phosphate batteries can use the cascade to use the remaining value, and the batteries of ternary materials are still mainly disassembled and recycled. Lithium battery recovery method and process (1) When the performance of the power lithium ion battery drops to 80% of the original performance, it will not meet the standard for electric vehicles, but it still has the energy storage system, especially the small-scale decentralized Conditions for continuous use in energy storage systems, such as stabilizing and stabilizing the output power of intermittent renewable energy power generation such as wind energy and solar energy, performing peak shaving and valley filling, reducing the contradiction between power supply and demand, and meeting the requirements of two-way interaction of smart grid energy. In addition, retired power lithium batteries can also be used in low-speed electric vehicles, such as electric bicycles and electric motorcycles. The huge demand for energy storage batteries for tower base stations is in line with the large-scale use of tiered batteries, and will become an important category for tiered batteries. On January 4, 2018, my country Tower Corporation and 16 companies including Changan Automobile, BYD, Yinlong New Energy, Watermark, Guoxuan High-Tech, Thornton New Energy and other 16 companies signed a strategic partnership for the recycling and utilization of new energy vehicle power batteries. protocol. my country's iron tower company currently has a pilot scale to 12 provinces and cities, and has built more than 3,000 experimental sites, covering various operating conditions such as power backup, peak shaving and valley filling, and microgrid. Echelon utilization in energy storage uses communication base station energy storage batteries that are in huge demand, which can absorb most of the waste power lithium batteries. According to the forecast of Zhiyan Consulting, the scale of global mobile communication base station investment is expected to reach 52.9 billion yuan in 2017, an increase of 4.34% year-on-year; in 2016, my country Mobile, my country Telecom and my country Unicom’s 4G base station construction numbers reached 300,000 and 290,000 respectively And 216,000, the annual replacement of the existing battery and the huge demand for the battery in the new base station. In the long run, cascade utilization can not only realize the reuse of decommissioned power lithium-ion batteries, but is also expected to guide the development of new energy utilization models. (2) Dismantling and recycling After discharging and disassembling the waste lithium battery in advance, according to the critical key technology adopted in the recycling process, the recycling process of the waste lithium battery can be divided into physical methods and chemical methods. And the three categories of biological law. The physical methods include fire method, mechanical flotation method, mechanical grinding method, organic solvent dissolution method and hydrothermal dissolution precipitation method. The fire method, also known as the dry method, is the most commonly used physical recycling method. It is important to remove the bonded organic matter through high-temperature incineration analysis to achieve the separation between the materials of the lithium battery pack, and at the same time, the metal and its compounds in the battery Oxidize, reduce and analyze. After volatilizing in the form of water vapor, it is collected by condensation method. The pyrotechnic process is simple and can effectively remove the electrolyte, binder and other organic substances in the battery, but the operation energy consumption is large, and if the temperature is too high, the aluminum foil will be oxidized into alumina, resulting in a decrease in value and difficulty in collection. At the same time, with regard to exhaust gas from high-temperature combustion, corresponding countermeasures must be studied to guard against environmental pollution. Chemical method (also known as wet method) is to use sodium hydroxide, sulfuric acid, nitric acid, hydrogen peroxide and other chemical reagents to purify, separate and purify the cobalt, lithium, and aluminum in the positive electrode of the lithium battery after disassembling and rupturing the lithium battery. Metal elements such as cobalt and lithium. Since the use of hydrochloric acid to leaching metal ions will generate harmful chlorine in the reaction, the most commonly used leaching system is a mixed system of sulfuric acid and hydrogen peroxide. For the leaching solution after acid leaching, precipitation, extraction, salting out, electrochemical methods and other methods can be used to achieve the purification of metal ions. The chemical method is relatively mature, and the recovery rate is higher than that of the physical method. However, metal oxides are generally obtained and cannot be used directly as cathode materials for lithium batteries. The subsequent use of recovered metal oxides to prepare cathode materials is more complicated and costly. high. Comparing the two processes, it can be found that the physical method can directly recover the positive electrode material, the negative electrode material electrolyte, and the separator, and can be used for the reprocessing of lithium batteries after simple solutions, but this method requires at least the positive and negative used by the waste lithium battery The electrode material and electrolyte are the same. However, in practice, there are many cathode materials for power lithium batteries. High-energy-density ternary materials can also be divided into 811, 522, 111 and other models according to their own composition ratios. Therefore, the physical method has not yet been commercialized and used, and the industry is generally Using relatively mature chemical methods. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: UPS power battery replacement methods and matters needing attention