Titanium Catecholate Synthesis via In Situ Oxychloride Intermediate
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Solution Overview
Problem
Conventional methods for producing titanium catecholate complexes are costly and incompatible with aqueous reaction conditions, limiting their scalability and purity for use in flow batteries, which hampers the performance and durability of these energy storage systems.
Innovation Solution
The use of titanium oxychloride as a low-cost titanium source in aqueous solutions, allowing for the synthesis of titanium catecholate complexes under acidic conditions, which promotes the formation of high-purity complexes that can be easily purified and used in flow batteries, thereby improving their performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If titanium tetrachloride is used as a starting material in conventional aqueous methods, then the cost is reduced, but the high water reactivity causes it to form hydrogen chloride and titanium dioxide which are not suitable precursors for forming titanium coordination complexes
Solution Approach 1:
The patent introduces titanium oxychloride as an intermediary substance that bridges the gap between titanium tetrachloride and suitable titanium coordination complexes. Titanium oxychloride is formed by controlled hydrolysis of titanium tetrachloride and serves as a stable intermediate that can be further reacted with catecholate ligands to form the desired complexes, thus enabling the use of low-cost titanium tetrachloride while avoiding the formation of unsuitable titanium dioxide
Solution Approach 2:
The patent applies preliminary action by pre-converting titanium tetrachloride to titanium oxychloride under controlled conditions before introducing catecholate ligands. This preliminary conversion step ensures that the titanium precursor is in the appropriate chemical form (titanium oxychloride rather than titanium dioxide) to subsequently form coordination complexes, thereby preventing the harmful side reaction with water that would produce unsuitable titanium dioxide
2Reliability
If conventional routes using titanium oxysulfate or titanium tetrakis(isopropoxide) are used, then suitable titanium coordination complexes can be formed, but the cost increases and scalability is limited
Solution Approach 1:
The patent employs titanium tetrachloride, a low-cost and readily available starting material, as a disposable precursor that is converted in situ to titanium oxychloride. This approach replaces expensive commercial titanium sources (titanium oxysulfate or titanium tetrakis(isopropoxide)) with a much cheaper alternative (titanium tetrachloride), thereby reducing material costs and improving scalability for commercial applications
Solution Approach 2:
The patent changes the chemical parameters of the titanium precursor by controlling the hydrolysis of titanium tetrachloride to form titanium oxychloride with specific water content (0.1-10 wt%) and acidity (pH 0-2). These parameter changes transform the reactive titanium tetrachloride into a stable intermediate form that maintains low cost while enabling subsequent complex formation, thus achieving both cost reduction and reliability
3Productivity
If aqueous methods are used to improve scalability and cost, then the reactivity of titanium tetrachloride with water causes formation of hydrogen chloride and titanium dioxide, but the invention enables high-purity titanium catecholate complexes to be formed in aqueous solution
Solution Approach 1:
The patent converts the harmful side reaction (hydrolysis of titanium tetrachloride producing titanium dioxide and hydrogen chloride) into a beneficial process by controlling it to produce titanium oxychloride instead. The controlled hydrolysis in aqueous solution with specific water content and acidity conditions transforms what would be waste products into the desired intermediate (titanium oxychloride) that enables subsequent complex formation, thus turning a harmful factor into a useful one
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 method enables the production of high-purity titanium catecholate complexes at lower costs, enhancing the energy storage efficiency and durability of flow batteries by allowing for higher concentration electrolyte solutions and reducing instability issues.
Implementation Method 1
combining one or more catecholate ligands and titanium oxychloride in an aqueous solution, and reacting the one or more catecholate ligands with the titanium oxychloride in the aqueous solution to form a titanium catecholate complex
Data Source
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AI summary
Titanium coordination complexes, particularly titanium catecholate complexes, can be attractive active materials for use in flow batteries. However, such coordination complexes can be difficult to prepare from inexpensive starting materials, particularly in aqueous solutions. Titanium oxychloride and titanium tetrachloride represent relatively inexpensive titanium sources that can be used for preparing such coordination complexes. Methods for preparing titanium catecholate complexes can include combining one or more catecholate ligands and titanium oxychloride in an aqueous solution, and reacting the one or more catecholate ligands with the titanium oxychloride in the aqueous solution to form the titanium catecholate complex. Titanium tetrachloride can be used as a precursor for forming the titanium oxychloride in situ. In some instances, the titanium catecholate complex can be isolated in a solid form, which can be substantially free of alkali metal ions.