Porous Graphene Cathode via Low-Temperature Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current graphene manufacturing methods face challenges with high thermal treatment temperatures, low yield, high production costs, and impurities, limiting the economic feasibility and purity of graphene, particularly for applications in secondary batteries where alternative cathode materials are needed due to the instability and safety concerns of LiCoO2.
Innovation Solution
A method involving the formation of graphite oxide, treated with hydrochloric acid and reduced at temperatures between 120°C and 200°C, eliminating the need for high-temperature thermal treatment and chemical reduction, resulting in a porous graphene suitable for high-voltage cathode applications in secondary batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-temperature thermal treatment (800°C or above) is used to reduce graphene oxide, then graphene can be produced, but the production cost increases and economic feasibility decreases
Solution Approach 1:
The patent changes the temperature parameter from high-temperature (800°C or above) to low-temperature (120-200°C) thermal treatment, combined with hydrochloric acid treatment, to reduce graphene oxide. This parameter change resolves the contradiction by achieving graphene production at lower costs while maintaining reliability.
2Reliability
If conventional reduction methods are used, then graphene oxide can be reduced, but impurities remain in the graphene
Solution Approach 1:
The patent introduces hydrochloric acid as an intermediary substance that facilitates the reduction of graphene oxide while removing impurities. The hydrochloric acid acts as a mediator between the thermal treatment process and the graphene oxide, enabling both reduction and purification simultaneously.
3Reliability
If existing graphene manufacturing methods are used, then graphene can be produced, but the yield is low due to poor efficiency
Solution Approach 1:
The patent applies preliminary hydrochloric acid treatment to graphene oxide before thermal reduction. This preliminary action modifies the graphene oxide structure in advance, making it more susceptible to reduction and significantly improving the overall yield and efficiency of the manufacturing process.
4Ease of manufacture
If LiCoO2 is used as cathode material, then secondary batteries can be manufactured, but safety problems occur due to structural instability and oxygen generation
Solution Approach 1:
The patent replaces the expensive and unsafe LiCoO2 cathode material with porous graphene, which is derived from abundant graphite resources. This substitution uses a more stable, cost-effective material that eliminates safety concerns related to structural instability and oxygen generation, while maintaining ease of manufacture.
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
This approach enables the mass production of high-purity graphene at a lower cost, with a porous structure and controlled functional groups, enhancing its electric conductivity and electrochemical reactivity, achieving a high capacity and power density as a cathode material for lithium and sodium secondary batteries.
Implementation Method 1
the hydrochloric acid-treated graphite oxide is reduced at temperature of 120° C. or above and 200° C. or below by performing thermal treatment thereto
Implementation Method 2
the hydrochloric acid-treated graphite oxide is reduced at temperature of 120° C. or above and 200° C. or below by performing thermal treatment thereto
Data Source
AI summary
In the graphene manufacturing method, a graphite oxide is formed from graphite, and then the graphite oxide is treated with a hydrochloric acid. The hydrochloric acid-treated graphite oxide is reduced at temperature of 120° C. or above and 200° C. or below by performing thermal treatment thereto. Since a low-temperature process is used for manufacturing graphene by performing thermal treatment at a relatively low temperature for a short time, this method has great economic feasibility and utilization. Due to a simple composing process and low thermal treatment temperature, graphene may be mass-produced with a low price. In particular, the graphene may be used as a cathode material for a lithium secondary battery, which exhibits a high capacity at a high voltage of 2V or above by reacting with Li, different from an anode material of a lithium secondary battery.