LFP Electrode Regeneration by Low-Temperature Delithiation and Relithiation
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Solution Overview
Problem
Current methods for recycling lithium iron phosphate (LFP) batteries are energy-intensive and inefficient, leading to environmental concerns and resource depletion, while direct chemical lithiation processes result in poor performance due to varying Li deficiency and side reactions.
Innovation Solution
A near zero-energy regeneration process that delithiates spent LFP to FePO4, followed by chemical lithiation or sodiation at low temperatures (25° C. to 100° C.) using oxidizers and lithiating or sodiating agents, producing high-performance LiFePO4 or NaFePO4 electrodes without high-temperature processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional leaching method is used for recycling LFP batteries, then electrode materials can be recovered, but complex leachate composition and multiple separation steps create large amounts of secondary waste
Solution Approach 1:
The patent extracts and recovers electrode materials (cathode and anode) directly from spent LFP batteries through mechanical disassembly and material separation, bypassing the conventional leaching process entirely. This extraction approach recovers valuable materials while avoiding the generation of complex leachate and secondary waste that characterizes traditional hydrometallurgical methods
Solution Approach 2:
The patent implements a comprehensive recovery system that collects and regenerates multiple components including cathode materials, anode materials, electrolyte, and aluminum foil from spent batteries. Each component is separately recovered and regenerated for reuse, eliminating the need for destructive leaching processes that generate harmful waste streams
2Quantity of substance
If combination method of calcination and leaching is used, then electrode materials can be processed, but high energy consumption is caused by heat-treating process and recovery rate is low due to burning into carbon dioxide
Solution Approach 1:
The patent converts the harmful effect of carbon dioxide formation during calcination into a benefit by completely avoiding the calcination process. Instead of burning carbon coatings and organic additives at high temperatures (which consumes energy and destroys materials), the method uses mild chemical treatments to remove these components, thereby preserving electrode materials and eliminating energy-intensive heat treatment
Solution Approach 2:
The patent fundamentally changes the processing parameters from high-temperature calcination (typically 400-900°C) to ambient or mild chemical treatment conditions. This parameter change eliminates the energy-intensive heating step while maintaining effective material recovery, and prevents the thermal decomposition that leads to carbon dioxide formation and material loss
3Quantity of substance
If direct chemical lithiation is used to supplement lithium concentration, then lithium deficiency can be addressed, but varying Li deficiency and side reactions result in poor performance
Solution Approach 1:
The patent performs preliminary characterization of the recovered electrode materials to determine their exact composition, lithium content, and structural state before regeneration. This preliminary analysis allows for precise formulation of the regeneration process parameters, ensuring optimal lithium supplementation without excessive addition that would cause side reactions or performance degradation
Solution Approach 2:
The patent implements a feedback-controlled lithiation process where the lithium supplementation is based on actual measurements of lithium deficiency in the recovered materials. By measuring the exact lithium content and structural state first, then adjusting the lithiation conditions accordingly, the process achieves consistent high-performance results without the variability and side reactions associated with fixed-ratio direct chemical lithiation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The process achieves efficient recycling and regeneration of LFP electrodes, delivering discharge capacities of 150 mAh/g for lithium-ion batteries and 150 mAh/g for sodium-ion batteries with capacity retention of 90% and 85% respectively, outperforming conventional methods.
Implementation Method 1
The present invention provides a process for near zero-energy regeneration of lithium iron phosphate (LiFePO4) or sodium iron phosphate (NaFePO4) electrodes by recycling spent Lithium ferro phosphate rechargeable batteries, wherein the process comprises the steps of: a. de-lithiating the spent LFP by adding an oxidizer
Implementation Method 2
b. chemically lithiating the FePO4 by adding a lithiating agent in a solvent based on the amount of FePO4 in stoichiometric ratio
Implementation Method 3
c. chemically sodiating the pure FePO4 by adding a sodiating agent in a solvent based on the amount of FePO4 in stoichiometric ratio
Data Source
AI summary
The present invention relates to a rechargeable battery and a process near zero-energy regeneration of electrodes by recycling spent rechargeable batteries. The present invention relates to a process for near zero-energy regeneration of lithium iron phosphate (LiFePO4) or sodium iron phosphate (NaFePO4) cathode by recycling spent Lithium ferro phosphate rechargeable batteries.