Amorphous Iron-Phosphate Electrode Active Material
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Solution Overview
Problem
Amorphous metal-phosphate complex electrode active materials fail to realize their theoretical capacity, resulting in limited charging and discharging characteristics due to their low capacity and inefficient synthesis methods.
Innovation Solution
Development of an amorphous iron-phosphate complex represented by AxMPyOz with a peak near 220 cm−1 in Raman spectroscopy, achieved through rapid cooling and mechanical energy application using a ball mill to change the short-range order of the amorphous structure, potentially enhanced by adding a conductivity modifier.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If amorphous metal-phosphate complex is used as electrode active material, then synthesis cost is reduced and synthesis time is shortened, but capacity is insufficient and theoretical capacity cannot be realized
Solution Approach 1:
The patent applies parameter changes by controlling the cooling rate during solidification to create an amorphous structure, and subsequently applying mechanical energy through ball milling to modify the short-range order. These parameter changes enable the material to achieve both rapid synthesis and high capacity by optimizing the atomic arrangement without crystallization.
Solution Approach 2:
The patent utilizes mechanical vibration through ball milling to apply mechanical energy to the amorphous metal-phosphate complex. This mechanical energy input changes the short-range order of the amorphous structure, thereby enhancing the capacity to realize theoretical capacity while maintaining the advantages of rapid synthesis.
2Ease of manufacture
If amorphous metal-phosphate complex is used as electrode active material, then synthesis cost is reduced, but charging and discharging characteristics are insufficient
Solution Approach 1:
The patent employs mechanical vibration through ball milling to enhance the charging and discharging characteristics of the amorphous metal-phosphate complex. The mechanical energy input modifies the atomic arrangement and improves ion transport pathways, thereby achieving reliable battery performance while maintaining cost-effective synthesis.
Solution Approach 2:
The patent changes the structural parameters of the amorphous material by controlling the cooling rate and applying mechanical energy. These parameter changes optimize the short-range order to improve charging and discharging characteristics without increasing synthesis cost, as the amorphous structure is maintained throughout the process.
3Quantity of substance
If mechanical energy is applied to change short-range order of amorphous structure, then capacity is enhanced, but additional processing step is required
Solution Approach 1:
The patent merges the synthesis and structure modification processes by applying mechanical energy through ball milling after rapid cooling. This combination allows the amorphous structure to be formed and then optimized in a continuous manner, enhancing capacity without requiring entirely separate processing stages.
Solution Approach 2:
The patent uses parameter changes in the form of mechanical energy input to modify the short-range order of the amorphous structure. This approach enhances capacity by optimizing atomic arrangement through a controllable parameter (mechanical energy) that can be applied during or after synthesis, adding minimal complexity to the overall 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
This approach enables the production of high-capacity electrode active materials with superior conductivity and charging/discharging characteristics, effectively increasing the capacity of nonaqueous electrolyte secondary batteries.
Implementation Method 1
an amorphising step for obtaining the amorphous transition metal complex by rapidly cooling a melt having the AxMPyOz composition
Implementation Method 2
a short-range order changing step for changing a short-range order of an amorphous structure by performing a process of applying mechanical energy
Data Source
AI summary
Electrode active material of the invention is mainly an amorphous transition metal complex represented by AxMPyOz (where x and y are values which independently satisfy 0≦x≦2 and 0≦y≦2, respectively, and z=(x+5y+valence of M)/2 to satisfy stoichiometry; also, A is an alkali metal and M is a metal element selected from transition metals), and has a peak near 220 cm−1 in Raman spectroscopy. Applying the electrode active material of the invention to a nonaqueous electrolyte secondary battery increases the capacity of the nonaqueous electrolyte secondary battery.