Metal-organic framework as a matrix for polyethylene glycol in thermal energy storage and preparations thereof
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional polyethylene glycol (PEG)-based phase change materials (PCMs) face challenges such as poor heat conductivity and potential leakage during the liquification energy storage cycle, and encapsulation in metal containers leads to supercooling issues.
Innovation Solution
A phase change material (PCM) is developed using a metal-organic framework (MOF) matrix, specifically cobalt or nickel-based MOFs with 1,3,5-benzene tricarboxylic acid (BTC), incorporating polyethylene glycol (PEG) to form agglomerated wave-like sheets with controlled pore structure and composition, enhancing thermal stability and energy storage efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If PEG is used as a PCM, then suitable melting temperatures and chemical characteristics are achieved, but poor heat conductivity occurs
Solution Approach 1:
The patent creates a composite material by incorporating PEG into a MOF matrix, combining the favorable thermal properties of PEG with the high surface area and porous structure of MOFs to achieve both suitable melting temperatures and improved heat conductivity
Solution Approach 2:
The patent utilizes the porous structure of metal-organic frameworks as a support matrix for PEG, where the high surface area and controlled pore size enhance thermal conductivity while maintaining the phase change properties of PEG
2Reliability
If PEG is used as a PCM, then non-toxicity and durability are achieved, but potential leakage during liquification occurs
Solution Approach 1:
The patent employs a porous MOF matrix with controlled pore sizes that physically confines PEG, preventing leakage during phase change while maintaining the durability and non-toxicity of PEG
Solution Approach 2:
The patent nests PEG molecules within the porous structure of the MOF matrix, creating a contained structure that prevents leakage while allowing the PEG to maintain its phase change properties
3Loss of substance
If PEG is encapsulated in a metal container, then leakage is prevented, but supercooling issues occur
Solution Approach 1:
The patent replaces metal container encapsulation with a porous MOF matrix that prevents leakage through physical confinement while allowing thermal contact that prevents supercooling
Solution Approach 2:
The patent uses the MOF matrix as an intermediary between the PEG and the external environment, providing both containment to prevent leakage and thermal pathways to prevent supercooling
4Reliability
If MOF matrix is used to contain PEG, then leakage and supercooling are addressed, but manufacturing complexity increases
Solution Approach 1:
The patent incorporates PEG into the MOF matrix during the synthesis process, performing the encapsulation action in advance during material fabrication rather than as a separate step, thereby simplifying the overall manufacturing process
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 PCM exhibits improved thermal conductivity, latent heat capacity, and stability, with latent heat values up to 156 J/g and thermal stability up to 400°C, effectively addressing leakage and supercooling issues while maintaining energy storage performance across multiple cycles.
Implementation Method 1
The high specific surface area and large pore volume, which are controllable features of transition metal-based MOFs, make them attractive candidates as support matrices for shape-stabilized PCMs
Implementation Method 2
The development of thermal energy storage systems based on phase-change materials (PCMs) has gained attention in the renewable energy sector
Implementation Method 3
The selection of an appropriate support matrix offers several appealing qualities, including a porous structure, distinct sorption capabilities, improved thermal conductivity
Data Source
AI summary
The present disclosure is directed to a phase-change material (PCM) including a metal selected from cobalt and nickel and reacted units of 1,3,5-benzenetricarboxylic acid (BTC) for thermal energy storage and method of preparation thereof. The metal and the reacted units of the carboxylic acid form a metal-organic framework (MOF). The PCM further includes polyethylene glycol (PEG) present within a matrix of the MOF with a weight ratio of the metal organic framework to the polyethylene glycol from 10:1 to 1:10. The PCM of the present disclosure is in the form of agglomerated layers of wave-like sheets.