Recycling method of wasted lithium-ion battery
In recent years, wasted lithium batteries have been increasing rapidly with the fast growth of consumer electronics and electronic vehicles(EVs).
According to the data of the GGII, in 2021 alone, the installed capacity of power lithium batteries in China’s top 10 EVs lithium battery companies reached 146.73 GWh.
Waste lithium ion cell contain a lot of precious metals and toxic substances. If not handled properly, it will negatively impact the environment and resources.
Therefore, many researchers have paid more attention to the demand for the recycling and reuse of precious metals in waste lithium-ion batteries. The current method for recycling wasted lithium-ion batteries includes the pyrometallurgical and hydrometallurgical processes.
Pyrometallurgical process
Pyrometallurgical is a standard method for recycling LIBs (lithium-ion batteries) by putting the discharged spent LIBs into a smelting furnace with a temperature above 1000 ℃ for smelting.
During the smelting process, organic substances such as separators, electrolytes, binders, and negative electrode graphite in spent lithium batteries are burnt and removed.
At the same time, materials with lower melting points are smelted into alloys of Cu, Co, Ni, etc. Materials with low boiling points and other compounds are recovered by condensation, and other impurities are transferred into the slag phase or gas.
Hydrometallurgical process
At present, Hydrometallurgy is widely used in the recycling of LIBs. Hydrometallurgy is a method to separate and collect valuable materials in spent lithium ion cell.
After leaching and reduction, the metal soluble salts or precipitates are obtained. It has the advantages of low investment, flexible production, and a high metal recovery rate.
The hydrometallurgical process of spent lithium batteries mainly includes pretreatment, leaching, purification and separation, and material regeneration.
The trend of recycling lithium batteries
Development of LIBs industry
The production and sales of electric vehicles in China have changed from what they used to be. China’s new energy vehicle industry has achieved leapfrog growth, from a faltering start to over 10 million electric vehicles.
In 2021, China produced 3.545 million electric vehicles, an increase of 2.179 million units from 2020. At the same time, the sales of electric vehicles were 3.521 million units, an increase of 2.154 million units from 2020.
2011-2021 Output and Sales of New Energy Vehicles in China
In recent years, China’s new energy industry, such as electric vehicles, developed fast.
At the same time, the improvement of wireless communication and intelligent technology, and the fast growth of emerging consumer electronic products, have effectively driven the expansion of consumer lithium-ion battery market demand.
China has become a significant producer and seller of li-ion batteries.In 2021, China produced 2.3264 million pieces of lithium-ion batteries, an increase of 23.4%.
2015-2021 China’s lithium-ion battery output and growth
According to Qichacha’s data, there are currently 40,000 lithium-ion battery-related companies in China. From 2014 to 2019, the number of registered lithium-ion battery-related companies in China has increased.
However, from 2020 to 2021, lithium-ion battery-related companies are declining. In 2021, the number of new registered lithium ion cell and related companies was 2,341 in China.
According to the regional division, Guangdong province has the most companies, followed by Jiangsu, Shandong, and other regions.
2015-2021 newly registered Li-on battery companies in China and their growth rate
(Only count companies whose names and business scope include lithium-ion batteries)
According to data from the Ministry of Industry and Information Technology of China, China’s total lithium-ion battery shipments were 158.5GWh in 2020, a year-on-year increase of 20.4%.
And in 2021, China’s lithium-ion battery output was 324GWh, a year-on-year increase of 106%.
2016-2021 total lithium-ion battery shipments and growth of China
Among the total output, there were 72GWh of consumption lithium batteries, 220GWh of power lithium batteries, and 32GWh of energy storage lithium batteries, up 18%, 165%, and 146%, respectively. In the meantime, the market share was 22.22%, 67.90%, and 9.88%, respectively.
2020-2021 China’s total lithium-ion battery shipments
2020-2021 The proportion of Shipments for different types of Li-ion batteries in China
Status of the recycling of lithium batteries in China
With the development of new energy industries involving li-ion batteries as energy storage devices, the demand for li-ion batteries is increasing, which inevitably leads to many lithium-ion batteries in the problem of waste, recycling and reuse.
As a consumable product, the average service life of li-ion batteries is only 3-5 years. The scrapped lithium-ion batteries may still contain the power, which may cause safety problems.
At the same time, spent batteries contain toxic materials (cobalt, manganese, etc.) and a large amount of organic matter (binder, electrolyte, etc.), which will cause severe pollution to our environment.
Therefore, how to develop a harmless treatment for spent li-ion batteries is urgent. Recycling spent lithium-ion batteries help resolve the shortage of metal resources.
Moreover, it will contribute to the sustainable development of the new energy industry involving lithium batteries in our country.
In 2021, theoretically, the recycling volume of spent lithium-ion batteries in China was as high as 591,000 tons.
Among them, the recycling volume of spent power batteries is 294,000 tons (accounting for 49.75%), the recycling volume of 3C products and small rechargeable lithium ion batteries is 242,000 tons (accounting for 40.95%), and other related lithium-ion batteries recycling is 55,000 tons (accounting for 9.30%).
China’s spent li-ion battery recycling volume is expected to reach 2.312 million tons by 2026.
2018-2026 Forcast of China’s Recycling Volume and Growth of Spent Li-ion Batteries
2021 Estimated Volume and Proportion of Spent Li-ion Battery Recycling in China
With the growth of downstream lithium battery demand, the price of upstream metal raw materials keeps rising. Therefore, the market price of valuable metals extracted from waste battery recycling has risen.
And the recycling volume of spent lithium ion cell has also shown an increasing trend. It is estimated that the recycling value of spent lithium-ion batteries in China will reach 94.32 billion Yuan in 2026, a year-on-year growth of 20.3%.
2022-2026 Estimated Volume and Growth Rate of Spent Li-ion Battery Recycling in China
Research progress on the technology of recycling lithium batteries
In 2021, to better support the “carbon peak carbon neutrality”, China’s lithium-ion battery industry mainly focused on the supply-side structural reform, such as speeding up the modernization of the supply chain, achieving rapid growth in the entire industry and continuously improving the supply capacity of advanced products.
So far, China has made great progress in the research of the pyrometallurgical and hydrometallurgical processes of recycling spent lithium-ion batteries.
The researchers have successfully extracted and separated materials such as Cu, Co, Ni, Fe, Li, Al, and Mn from rechargeable lithium-ion batteries. The basic principles and technological methods have been gradually formed.
However, there is still massive room for improvement in recycling waste lithium-ion batteries.
High-precision intelligent sorting
Currently, the pretreatment of spent lithium battery recycling help gathers active material and recover copper, aluminum, iron and other resources through steps such as discharge, crushing, and sorting.
However, due to the insufficient refinement in the process of battery disassembly and crushing, copper, aluminum, iron, and other materials will still mix with the active material, which increases the dosage of leaching chemicals. And it also made the removal of impurities more difficult in the leaching process.
With the development of high-precision intelligent sorting technology, we can now separate the positive and negative fluids, iron shells, battery separators and other materials in advance.
It dramatically reduces the impurities in the active material and controls the quality of the entire recycling process and the final recycled products.
Pollution Control and Recovery of Electrolyte
Spent lithium batteries are flammable and explosive. Moreover, toxic components such as fluorine-containing electrodes are easily exposed to the air and pollute the environment. We must pay more attention to this issue during the recycling process.
In addition, the existing technologies primarily focus on extracting and utilizing valuable components. But we pay less attention to electrolyte recovery.
The electrolyte has a low boiling point and is easy to hydrolyze. If we cannot do non-hazardous treatment, it will inevitably lead to serious environmental problems. In return, it will restrict the recycling of spent lithium batteries.
Short & green recycling process and controllable preparation of high-added-value recycled materials
The leaching solution of waste lithium ion cell can be less efficient as the component of leaching is complex and it isn’t easy to extract. To resolve the problem of the long separation process of similar metals and the low added value of products, we need to design closed-circuit cycle recycling and directly regenerate the cathode material.
However, due to the impurities in the solution, in particular, the influence mechanism of trace impurities on the properties of regenerated products is unclear, resulting in insufficient consistency of regenerated products.
Therefore, systematically researching the relationship between the properties of leaching solution, material preparation methods and recycled products, and constructing a short-process green recycling system based on high-value-added functional materials, plays a vital role in improving the economic recycling of spent lithium ion cell.
