Eddy current separation for recovering aluminium and lithium-iron phosphate components of spent lithium-iron phosphate batteries

A review on the recycling of spent lithium iron phosphate batteries

Lithium iron phosphate (LFP) batteries have gained widespread recognition for their exceptional thermal stability, remarkable cycling performance, non-toxic attributes, and cost-effectiveness. However, the increased adoption of LFP batteries has led to a surge in spent LFP battery disposal. Improper handling of waste LFP batteries could result in adverse consequences, including environmental degradation and the mismanagement of valuable secondary resources. This paper presents a comprehensive examination of waste LFP battery treatment methods, encompassing a holistic analysis of their recycling impact across five dimensions: resources, energy, environment, economy, and society. The recycling of waste LFP batteries is not only crucial for reducing the environmental pollution caused by hazardous components but also enables the valuable components to be efficiently recycled, promoting resource utilization. This, in turn, benefits the sustainable development of the energy industry, contributes to economic gains, stimulates social development, and enhances employment rates. Therefore, the recycling of discarded LFP batteries is both essential and inevitable. In addition, the roles and responsibilities of various stakeholders, including governments, corporations, and communities, in the realm of waste LFP battery recycling are also scrutinized, underscoring their pivotal engagement and collaboration. Notably, this paper concentrates on surveying the current research status and technological advancements within the waste LFP battery lifecycle, and juxtaposes their respective merits and drawbacks, thus furnishing a comprehensive evaluation and foresight for future progress.

A novel process for multi-stage continuous selective leaching of lithium from industrial-grade complicated lithium-ion battery waste

Lithium-ion batteries are widely used in fields such as electric vehicles, portable electronic devices, energy storage systems, and medical equipment, and their indispensable and irreplaceable characteristics are highly regarded. However, extensive disposal of lithium-ion batteries occurs due to severe electrochemical property degradation. These waste batteries, as high-grade secondary resources, have become exceedingly valuable, especially given their lithium content far exceeding the mineable grade from conventional mining processes. Recovering this lithium not only contributes to the circular utilization of resources but also yields substantial economic benefits. This paper presents an innovative method that directly and selectively leaches lithium from industrial-grade composite lithium-ion battery waste. Unlike conventional methods, which require the separation of cathode active materials from other components, this method directly acts on complicated mixed powders, achieving a high leaching rate of lithium and exceptional leaching selectivity (Li extraction rate is higher than 96 %, while the extractions of iron, copper, aluminum, nickel, cobalt, and manganese are all lower than 1 %). Furthermore, a multi-stage continuous leaching process has been developed, enabling efficient selective leaching and enrichment of lithium from industrial-grade mixed waste materials. This method is suitable for various compositions of industrial lithium-ion battery waste and has demonstrated excellent industrial prospects in mini-pilot industrial experiments. Additionally, the paper investigates the washing, purification, and precipitation processes, resulting in a high-concentration and high-purity lithium-rich solution after four-stage washing and two-stage purification. And battery-grade lithium carbonate can be obtained after precipitation. Moreover, the economic evaluation calculations confirm that this method is profitable and feasible. This new method offers advantages such as high leaching rates, excellent selectivity, a streamlined process, low costs, wide applicability, environmental friendliness, and feasibility for industrialization. It represents efficient and sustainable technology with promising applications.

Advances and challenges in anode graphite recycling from spent lithium-ion batteries

Spent lithium-ion batteries (LIBs) have been one of the fast-growing and largest quantities of solid waste in the world. Spent graphite anode, accounting for 12-21 wt% of batteries, contains metals, binders, toxic, and flammable electrolytes. The efficient recovery of spent graphite is urgently needed for environmental protection and resource sustainability. Recently, more and more studies have been focused on spent graphite recycling, while the advance and challenges are rarely summarized. Hence, this study made a comprehensive review of graphite recycling including separation, regeneration, and synthesis of functional materials. Firstly, the pretreatment of graphite separation was overviewed. Then, the spent graphite regeneration methods such as leaching, pyrometallurgy, their integration processes, etc. were systematically introduced. Furthermore, the modification strategies to enhance the electrochemical performance were discussed. Subsequently, we reviewed in detail the synthesis of functional materials using spent graphite for energy and environmental applications including graphene, adsorbents, catalysts, capacitors, and graphite/polymer composites. Meanwhile, we briefly compared the economic and environmental benefits of graphite regeneration and other functional materials production. Finally, the technical bottlenecks and challenges for spent graphite recycling were summarized and some future research directions were proposed. This review contributes to spent LIBs recycling more efficiently and profitably in the future.

Recent advances in pretreating technology for recycling valuable metals from spent lithium-ion batteries

In recent years, the amount of spent lithium-ion batteries (LIBs) increase sharply due to the promotion of new energy vehicles and the limited service life. Recycling of spent LIBs has attracted much attention because of the serious environmental pollution and high economic value. Although some established techniques have been presented in spent LIBs recycling process, but most of them focus on cathode material recycling due to its high economic value. Therefore, preparation of high purity cathode material by a proper pretreating technology is an important procedure. In this paper, the technologies used in the pretreating process of spent LIBs are summarized systematically from three main points of discharging procedure, liberation, and separation. The collaborative application of multi-technologies is the key to realize efficient pretreating process, which can lay the foundation for the subsequent metallurgical process. In addition, an alternative pretreating flowchart of spent LIBs is proposed based on the multi-process collaboration. Pretreating procedures in this process are mainly based on the physical property difference, and they include "Discharging-Shredding-Crushing-Sieving-Separation".

Countercurrent leaching of Ni, Co, Mn, and Li from spent lithium-ion batteries

This study focuses on a countercurrent leaching process (CLP) for the dissolution of high-value metals from cathode active material of spent lithium-ion batteries (LIBs). Its main aim is to improve the effective utilization of acid during leaching and allow for the continuous operation of the entire CLP by adjusting the process parameters. The overall recovery of lithium (Li), cobalt (Co), nickel (Ni), and manganese (Mn) was 98%, 95%, 95%, and 92%, respectively; the acid utilization of the leaching process exceeded 95% under optimum conditions. The optimum conditions for first stage leaching were 70 g/L solid-liquid (S/L) ratio at 40°C for 30 minutes, and 2.0 M sulfuric acid, 100 g/L S/L ratio, 7 g/L starch, at 85°C for 120 minutes for second stage leaching. After five bouts of circulatory leaching, more than 98% Li, 95% Co, 95% Ni, and 92% Mn were leached under the same leaching conditions. Furthermore, we introduced the Avrami equation to describe metal leaching kinetics from spent LIBs, and determined that the second stage leaching process was controlled by the diffusion rate. In this way, Li, Ni, Co, and Mn can be recovered efficiently and the excess acid in the leachate can be reused in this hydrometallurgical process, potentially offering economic and environmental benefits.

Conductivity Classification of Non-Magnetic Tilting Metals by Eddy Current Sensors

Metallic waste classification benefits the environment, resource reuse and industrial economy. This paper provides a fast, non-contact and convenient method based on eddy current to classify metals. The characteristic phase to characterize different conductivity is introduced and extracted from mutual inductance in the form of amplitude and phase. This characteristic phase could offer great separation for non-tilting metals. Although it is hard to classify tilting metals by only using the characteristic phase, we propose the technique of phase compensation utilizing photoelectric sensors to obtain the rectified phase corresponding to the non-tilting situation. Finally, we construct a classification algorithm involving phase compensation. By conducting a test, a 95% classification rate is achieved.