Haozheng Hu,Xianghao Meng,Yin Li,Yusong Yang,Yanqiu Xu,Junxian Hu,Yaochun Yao
In the era of extensive deployment of LiFePO4 batteries in energy storage and electric vehicle domains, the recycling of lithium from spent LiFePO4 (SLFP) batteries has emerged as a focus, which helps in alleviating environmental pollution and resource shortages. Traditional recycling techniques, encompassing pyrometallurgical and hydrometallurgical methods, are often marred by low selectivity and extraction efficiency. Herein, an eco-friendly and low-consumption recycling strategy involving potassium pyrosulfate (K2S2O7)-assisted low-temperature roasting and subsequent water leaching has been developed for selectively recycling Fe and Li from SLFP batteries. The proposed strategy, compared to the conventional inorganic acid leaching method, mitigates the environmental hazards caused by acidic wastewater generation and reduces the costs associated with wastewater treatment. Investigations of thermal performance characterization and thermodynamic calculation analyses have revealed that K2S2O7 plays a pivotal role in extracting lithium from the Fe–P–O framework, converting lithium into a soluble sulfate variant and iron into insoluble compounds. This process culminates in the segregation of a lithium-rich leachate and an iron-enriched residue, which are further processed to synthesize Li2CO3 and FePO4. The effects on Li leaching of the mass ratio of K2S2O7 to SLFP, roasting time, roasting temperature, and water leaching time are systematically studied and 95.87% Li was leached in water under optimal conditions. In addition, the feasibility of the strategy was further illustrated by the regeneration of LiFePO4 produced by the recycled Li2CO3 and FePO4. Overall, this recovery strategy stands out for its effective lithium-iron segregation, environmental sustainability, and economic viability, which provide some inspiration for high-efficiency and environmentally friendly recovery metal from spent lithium-ion batteries.
In recent years, the large consumption of lithium-ion batteries (LiBs) has caused resource waste and environmental pollution. It is crucial to recycle and reuse LiBs, especially the valuable elements from the spent LiBs. In this research, a new, sustainable, and easy-to-implement process for the recycling of spent LiFePO4 cathode powder is proposed. 732 cation exchange resin is used as a leaching agent and an adsorbent to leach and adsorb Li and Fe from the spent LiFePO4 powder. The effects of various parameters, such as the cathode scrap-to-resin ratio (1/9), time (35 min), water addition (30 mL), and reaction temperature (30 °C), on the resin leaching and adsorption of the waste LiFePO4 cathode powder have been investigated. The effect of acid concentration on the elution rate during resin elution and experiments on the recyclability of the resin has been carried out as well. The results indicate that it is technically and economically feasible and environmentally friendly to use the 732 cation exchange resin to recover the waste LiFePO4 cathode powder. Products including high-purity Li2CO3 (99.95%), Fe2O3, and high-purity phosphoric acid can be obtained based on this process, through which a full component recovery with a high recovery rate was achieved. We investigated the reaction of kinetic analysis and also explored the effect of reaction conditions on the reaction. In contrast to previous studies on spent LiFePO4 cathode powder, our approach is promising and is analyzed as follows: (1) the 732 cation exchange resin has a dual role in the recycling process of used LiFePO4 cathode powder (leaching-adsorption) in the used LiFePO4 cathode powder recycling process. (2) The separation of the valued metals and the phosphoric acid can be achieved in one step using the 732 cation exchange resin.
危险品化学品经营许可证（带存储）