Recovery of Lithium Iron Phosphate by Specific Ultrasonic Cavitation Parameters

Abstract

With the widespread use of lithium iron phosphate batteries in various industries, the amount of waste lithium iron phosphate batteries is also increasing year by year, and if not disposed of in a timely manner, will pollute the environment and waste a lot of metal resources. In the composition of lithium iron phosphate batteries, the cathode has an abundance of elements. The ultrasonic method is a crucial method to recover waste LiFePO4 batteries. It has the following disadvantages, such as the lack of empirical parameters and suitable research equipment. In order to overcome the inefficiency of the LiFePO4 recycling method, the airborne bubble dynamical mechanism of ultrasound in the removal of lithium phosphate cathode material was studied by a high-speed photographic observation and Fluent simulation and the disengagement process. Mainly aimed at the parameters such as action time, power, frequency, and action position in the detachment process were optimized. The recovery efficiency of lithium iron phosphate reached 77.7%, and the recovered lithium iron phosphate powder has good electrochemical properties, with the first charge–discharge ratio of up to 145 (mAh)/g. It is shown that the new disengagement process established in this study was adopted for the recovery of waste LiFePO4.

Review of Ultrasound-Assisted Recycling and Utilization of Cathode Materials from Spent Lithium-Ion Batteries: State-of-the-Art and Outlook

“…The application of ultrasound can further improve the separation efficiency. However, the complete liberation of cathode materials from Al foil in water can be achieved with the severe corrosion of Al foil . These entrapped Al powders in the cathode material particles are harmful to the subsequent processing of cathode materials.…”

“…However, increasing the power from 50 to 100 W reduces the separation efficiency of the cathode powder, which is perhaps because a large number of cavitation bubbles creates obstacles for transferring sound energy to other parts of the tank, and the physical vibration of the transducer is greater than the ability of fluids to maintain contact . In addition, the ultrasonic treatment can damage the Al foil to some degree, causing some Al debris to be mixed into stripped cathode active substances, which requires further screening and processing …”

“…These impurities mixed with the Al foil enter the cathode material, which is not conducive to the subsequent utilization of the cathode material. 44 3.2. Organic Solvents.…”

“…However, the complete liberation of cathode materials from Al foil in water can be achieved with the severe corrosion of Al foil. 44 These entrapped Al powders in the cathode material particles are harmful to the subsequent processing of cathode materials. According to the general "like likes like" rule, it is indisputable that organic solvents assisted by ultrasound can completely separate cathode materials from Al foil.…”

“…It is widely accepted that the complete degradation of organic binders when immersed under water requires a long time of ultrasonic treatment, which may cause serious Al foil corrosion. These impurities mixed with the Al foil enter the cathode material, which is not conducive to the subsequent utilization of the cathode material …”