Reduced Acylated Graphene Oxide for High-Capacity Stable Anodes
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Solution Overview
Problem
Existing lithium secondary batteries face limitations in achieving high energy density due to the limited lithium ion storage capacity of carbon-based materials like graphite, and non-carbon-based materials suffer from volume changes during lithium reactions, leading to stability issues.
Innovation Solution
The development of reduced acylated graphene oxide as a negative electrode active material, prepared through an acylation and reduction process, which forms a three-dimensional structure with R—C(═O)— or R—C(═O)O— groups, using carbonaceous powder as a reducing agent and microwave irradiation to minimize structural changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If graphite is used as negative electrode active material, then reversible charge and discharge characteristics are achieved, but lithium storage capacity is limited to about 370 mAh/g
Solution Approach 1:
The patent uses acylated graphene oxide as a composite material that combines the reversible charge-discharge characteristics of graphite with enhanced lithium storage capacity. The acylated structure creates additional lithium ion insertion sites beyond the standard graphite intercalation, achieving both reliability and higher capacity
Solution Approach 2:
The patent modifies the chemical structure of graphene oxide through acylation, changing the C/O ratio and creating new chemical environments for lithium storage. This parameter change enables the material to exceed the theoretical 370 mAh/g limit of conventional graphite while maintaining reversible electrochemical behavior
2Quantity of substance
If non-carbon-based materials like silicon or tin are used, then higher theoretical capacity is achieved, but volume change occurs during lithium reaction
Solution Approach 1:
The patent changes the chemical composition parameters of the negative electrode material by introducing acyl groups with specific C1 or higher alkyl and C5 or higher aryl structures. This modification enables the material to achieve higher lithium storage capacity while maintaining structural stability and minimizing volume change during cycling
Solution Approach 2:
The acylated graphene oxide acts as a composite material that combines the high capacity potential of non-carbon materials with the structural stability of carbon-based frameworks, achieving both high theoretical capacity and volume stability simultaneously
3Quantity of substance
If acylation reaction is performed on graphene oxide, then lithium storage capacity is increased, but process complexity increases
Solution Approach 1:
The patent optimizes the acylation process parameters including the C/O ratio control, reaction conditions, and reduction steps to achieve the desired lithium storage capacity enhancement while keeping the process manageable and suitable for practical application
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 reduced acylated graphene oxide exhibits improved battery capacity, reduced resistance, and stable cycle characteristics, enhancing the performance of lithium secondary batteries, redox flow batteries, and lithium-air batteries.
Implementation Method 1
subjecting graphene oxide to an acylation reaction to prepare acylated graphene oxide
Implementation Method 2
reducing the acylated graphene oxide... the reducing of (b) may be performed in the presence of a solid reducing agent, the solid reducing agent may be carbonaceous powder
Implementation Method 3
the reducing of (b) may be performed by irradiating a mixture of the acylated graphene oxide and the reducing agent with microwaves
Data Source
AI summary
Provided are reduced acylated graphene oxide as an electrode active material and a method for preparing the same. By the method for preparing reduced acylated graphene oxide according to the present invention, a negative electrode active material for a lithium secondary battery having stable activity and a high battery capacity may be prepared with a simple and low-cost process. In addition, the active material prepared by the preparation method has low resistance, a high battery capacity, and improved rate-limiting characteristics while having stable cycle characteristics.