Lithium iron phosphate (LFP) has found many applications in the field of electric vehicles and energy storage systems. However, the increasing volume of end‐of‐life LFP batteries poses an urgent challenge in terms of environmental sustainability and resource management. Therefore, the development and implementation of efficient LFP battery recycling methods are crucial to address these challenges. This article presents a novel, comprehensive evaluation framework for comparing different lithium iron phosphate relithiation techniques. The framework includes three main sets of criteria: direct production cost, electrochemical performance, and environmental impact. Each criterion is scored on a scale of 0–100, with higher scores indicating better performance. The direct production cost is rated based on material costs, energy consumption, key equipment costs, process duration and space requirements. Electrochemical performance is assessed by rate capability and cycle stability. Environmental impact is assessed based on CO2 emissions. The framework provides a standardized technique for researchers and industry professionals to objectively compare relithiation methods, facilitating the identification of the most promising approaches for further development and scale‐up. The total average score across the three criterion groups for electrochemical, chemical, and hydrothermal relithiation methods was approximately 60 points, while sintering scored 39 points, making it the least attractive relithiation technique. Combining approaches outlined in publications with scores exceeding 60, a relithiation scheme was proposed to achieve optimal electrochemical performance with minimal resource consumption and environmental impact. The results demonstrate the framework's applicability and highlight areas for future research and optimization in lithium iron phosphate cathode recycling.
1 March 2019 in International Journal of Electrochemical Science
The electrolyte is an important component of lithium-ion batteries, especially when it comes to cycling high-voltage cathode materials. In this paper, we propose an algorithm for estimating both the oxidising and reducing potential of electrolytes using molecular dynamics and quantum chemistry techniques. This algorithm can help to determine the composition and structure of the solvate complexes formed when a salt is dissolved in a mixture of solvents. To develop and confirm the efficiency of the algorithm, LiBF4 solutions in binary mixtures of ethylene carbonate (EC)/dimethyl carbonate (DMC) and sulfolane (SL)/dimethyl carbonate (DMC) were studied. The structure and composition of the complexes formed in these systems were determined according to molecular dynamics. Quantum chemical estimation of the thermodynamic and oxidative stability of solvate complexes made it possible to establish which complexes make the most significant contribution to the electrochemical stability of the electrolyte system. This method can also be used to determine the additive value of the oxidation and reduction potentials of the electrolyte, along with the contribution of each complex to the overall stability of the electrolyte. Theoretical calculations were confirmed experimentally in the course of studying electrolytes by step-by-step polarisation using inert electrodes. Thus, the main aim of the study is to demonstrate the possibility of using the developed algorithm to select the optimal composition and solvent ratio to achieve predicted redox stability.
The effect of a protective coating of fused lithium borate, Li3BO3, on the physicochemical and electrochemical characteristics of LiCoO2 has been studied. A cathode material produced by the SCS method using binary organic fuel, glycine and citric acid. The influence of the experiment conditions on the morphology, crystal structure and specific surface of lithium cobaltite was studied. Electrochemical testing of LiCoO2∙nLi3BO3 samples, n = 5 and 7 mass %, has been performed in the cathode Li|Li+-electrolyte|LiCoO2∙nLi3BO3 half-cell using 1M LiPF6 in EC/DMC mixture (1:1) as electrolyte in the 2.7-4.3 V range at normalized discharge current С/10, С/5, С/2. The maximal initial discharge capacity of 185 mAh/g was detected for the samples with 5 mass % Li3BO3. The coulomb efficiency of optimal materials in the 40th cycle was 99.1%.