Silicon-Carbon Composite Anode from Recovered Graphite
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The recycling of lithium-ion battery (LIB) anodes is inefficient, leading to resource waste and environmental concerns, as existing methods are costly, complex, and not scalable for industrial production.
Innovation Solution
A silicon-carbon composite anode material is prepared using a method that involves purifying recovered graphite anode powder through acid leaching and heat treatment, and then mixing it with modified silicon powder and a polyimide (PI)-containing N,N-dimethylformamide (DMF) solution, followed by distillation and carbonization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If existing recycling methods are used for LIB anodes, then some recovery is achieved, but the process is costly, complex, and not scalable for industrial production
Solution Approach 1:
The patent changes the chemical parameters of the recycling process by using specific acid solutions (hydrochloric acid, sulfuric acid, or nitric acid) with controlled concentrations and temperatures to dissolve metal impurities from graphite anodes. This chemical parameter approach simplifies the process while maintaining industrial scalability, replacing complex physical separation methods with a straightforward chemical treatment that can be easily implemented at scale.
Solution Approach 2:
The patent utilizes phase transitions in the form of controlled precipitation and filtration. After acid treatment, metal impurities precipitate out of solution as solid particles that can be easily separated from the graphite powder through filtration. This phase transition approach converts dissolved impurities into removable solid forms, simplifying the purification process and enabling industrial-scale operation.
2Loss of substance
If graphite anode powder is recovered from scrapped LIBs, then resource waste is reduced, but purification is required to remove metal impurities
Solution Approach 1:
The patent extracts metal impurities from recovered graphite anode powder through selective acid dissolution. The acid solution specifically targets and dissolves metal contaminants while leaving the graphite material intact. This extraction process removes impurities in a single step, simplifying the overall purification process compared to multiple sequential treatment steps.
Solution Approach 2:
The patent uses acid solution as an intermediary medium to facilitate the separation of metal impurities from graphite. The acid acts as a mediator that selectively interacts with metal particles, dissolving them into the solution while allowing clean graphite to be filtered and recovered. This intermediary approach simplifies the purification process by providing a clear separation mechanism.
3Quantity of substance
If silicon powder is added to graphite material, then specific capacity is improved, but mixing and processing complexity increases
Solution Approach 1:
The patent merges silicon powder with purified graphite material through simple mixing and sintering processes. The silicon particles are uniformly distributed within the graphite matrix, creating a composite anode material that combines the high capacity of silicon with the structural stability of graphite. This merging process is straightforward and can be easily scaled for industrial production.
Solution Approach 2:
The patent creates a composite anode material by combining silicon and graphite in a controlled manner. The composite structure leverages the complementary properties of both materials: silicon provides high lithium storage capacity while graphite provides structural integrity and conductivity. This composite approach achieves enhanced performance without requiring complex processing equipment or multi-step manufacturing procedures.
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 method achieves a specific capacity of 670 mAh/g to 760 mAh/g for initial lithium intercalation, a capacity retention of 95% to 97% after 50 cycles, and low production costs, making it suitable for industrial-scale recycling and reuse of LIB anodes.
Implementation Method 1
dissolving a graphite anode powder in an acid solution, and conducting solid-liquid separation (SLS) to obtain a precipitate
Implementation Method 2
washing and drying the precipitate, adding a reducing agent, and subjecting a resulting mixture to heat treatment to obtain a purified graphite material
Implementation Method 3
subjecting a resulting mixture to heat treatment
Implementation Method 4
adding a resulting mixture to a polyimide (PI)-containing N,N-dimethylformamide (DMF) solution, and stirring; and subjecting a resulting mixture to distillation
Implementation Method 5
subjecting a resulting mixture to distillation and then to carbonization to obtain the silicon-carbon composite anode material
Data Source
AI summary
The present disclosure belongs to the technical field of battery materials, and discloses a silicon/carbon composite anode material, and a preparation method and use thereof. The preparation method includes the following steps: S1. dissolving a graphite anode powder in an acid solution, and conducting solid-liquid separation (SLS) to obtain a precipitate; and washing and drying the precipitate, adding a reducing agent, and subjecting a resulting mixture to heat treatment to obtain a purified graphite material; and S2. mixing a modified silicon powder with the graphite material, adding a resulting mixture to a polyimide (PI)-containing N,N-dimethylformamide (DMF) solution, and stirring; and subjecting a resulting mixture to distillation and then to carbonization to obtain the silicon/carbon composite anode material.