Where is the future of iron lithium battery?
- A big gap between practice and theory of cascade utilization
- The price of iron and lithium waste is rising
- The recycling of iron-lithium batteries is mainly based on regeneration
According to statistics, in the first half of this year, the cumulative installed capacity of power batteries in China was 110.1GWh, a year-on-year increase of 109.8%. Among them, the cumulative loading of lithium iron phosphate batteries is 64.4GWh, accounting for 58.5% of the total loading, with a cumulative increase of 189.7% year-on-year.
As the application of lithium iron phosphate batteries in the field of electric new energy vehicles continues to grow, the number of retired lithium iron phosphate batteries will continue to increase in the future.
In theory, the cycle life of lithium iron phosphate batteries is about 5 years, and the battery capacity should enter the recycling process after the battery capacity decays to 70%-80%. Due to its high safety and long cycle life, retired lithium iron phosphate batteries are first used in various scenarios, such as toy cars, communication base stations, and energy storage projects with relatively low requirements.
At present, various policy subsidies for the cascade utilization of decommissioned lithium batteries have been introduced in various places, which effectively promotes the cascade utilization of lithium ion battery recycling, such as toy cars, communication base stations, and energy storage projects with relatively low requirements. After the cascade utilization, the capacity decays to about 30% and then enters the crushing and powdering process.
A big gap between practice and theory of cascade utilization
Restricted by the detection technology and application scenarios, there is a gap between the actual and the theory of cascade utilization. But with the passage of time, enterprises of cascade utilization have gradually realized the gap between theory and practical application.
The lithium iron phosphate batteries that have come down the ladder mainly have the following two drawbacks: one is brought about by the current detection technology, and the other is caused by the limited application scenarios. First of all, the immaturity of detection technology, especially the rapid detection technology, makes it difficult to detect the cycle life of batteries from recycling and transportation to evaluation and detection.
This makes it difficult to guarantee the performance and consistency of retired batteries, and there are potential safety hazards. If it is applied to energy storage projects on a large scale, in order to increase safety, a higher cost battery management system is required; at the same time, there is still controversy over whether retired lithium iron phosphate is suitable for low-speed vehicles. Although it has better safety performance, its low energy density is difficult to ensure the endurance of low-speed vehicles.
Therefore, at present, most of the iron-lithium batteries cannot be used in a good cascade. In fact, the capacity decays to about 60%, and most of them enter the crushing and powdering process.
The price of iron and lithium waste is rising
Recently, the price of scrap iron-lithium soft packs has increased by 310% since the beginning of this year, the steel shell has increased by 512%, and the aluminum shell has increased by 231%. One of the most economical actions to recover lithium iron waste is to extract lithium, and the price of lithium carbonate has continued to rise this year. The supply speed of raw ore mining and lithium extraction from salt lakes has not been able to meet downstream production needs. Highly valued, the price of iron-lithium scrap has also been rising.
However, after August this year, due to the excessive bullish sentiment in the market for lithium carbonate, the price of waste batteries gradually deviates from the actual production value. According to the data, the gross profit of iron-lithium waste has been negative since September this year. After the iron-lithium battery is powdered, the average loss of manufacturers is about 2000-4000RMB/ton.
In this case, the willingness of the crushing and milling plant to recycle the powder is very low, and it is unable to obtain profit from it, which dampens the enthusiasm for production to a certain extent. However, this is a short-term situation caused by the current mismatch between the supply and demand of lithium carbonate and the shortage of waste materials. In the later stage, with the balance of supply and demand of lithium carbonate and the increase in the volume of retired lithium iron batteries, this situation will be effectively alleviated.
The recycling of iron-lithium batteries is mainly based on regeneration
With the continuous growth of the application of lithium iron phosphate batteries in the field of electric new energy vehicles, the number of retired lithium iron phosphate batteries will continue to increase in the future. In the short and medium term, under the condition that the cascade utilization technology is not fully mature, the iron-lithium battery cannot perfectly establish the role of the cascade, and its value will be more reflected in the field of regeneration.
But at present, just extracting lithium cannot have greater competitiveness on the purchasing side. If more recycling value can be obtained from scrap iron lithium batteries (such as recovery of iron phosphate, recovery of electrolyte, etc.), It will have a greater advantage in the procurement of iron-lithium batteries. That is to say, the recycling of iron-lithium batteries, whether it is echelon or regeneration, is essentially a difficult battle.
When the recycled material is a mixed recycled material with complex components, it is suitable to use chemical precipitation or bioleaching technology for metal recovery to obtain chemical materials that can be reused. However, for LiFePO4 materials, wet recycling has a long process and needs to use problems such as more acid-base reagents and processing a large amount of acid-base waste liquid have the disadvantages of high recovery cost and low economic value.
Compared with the chemical precipitation recovery technology, the high temperature repair and high temperature regeneration technology has the advantages of short process, less acid and alkali reagents, and less waste acid and waste alkali.
However, this method requires strict impurity removal of recycled materials before remediation or regeneration treatment to avoid impurity residues affecting the electrochemical properties of the material. Impurities include a small amount of aluminum foil, copper foil, etc. The problem of impurity removal is an important problem that direct repair and regeneration technology has not been studied in large-scale applications but must be solved.
In order to improve the economic value of waste battery recycling, low-cost electrolyte and lithium ion battery anode material recycling technology should be further developed to maximize the recovery of useful substances in waste batteries and maximize recycling benefits.