Transition Metal Hydroxide Precursor for Stable Cathode Firing
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Solution Overview
Problem
Secondary batteries, such as lithium ion batteries, face issues with battery capacity and cycle characteristics due to the elution of additive metal elements during firing, which affects the stability and safety of the battery.
Innovation Solution
A transition metal-containing hydroxide is produced with controlled heat capacity using differential scanning calorimetry, preventing segregation by adjusting the temperature range and raw material solution addition rate, and incorporating a complexing agent like an ammonium ion donor to ensure uniform dispersion and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the firing temperature is increased to improve battery capacity, then the reactivity between transition metal-containing hydroxide and lithium compound improves, but additive metal elements may be eluted by phase transition or segregation
Solution Approach 1:
The patent applies preliminary action by controlling the particle size of the transition metal-containing hydroxide precursor to 10 μm or less before firing. This pre-processing step ensures that the fine particles react more completely at lower firing temperatures (900-1000°C), preventing additive metal element segregation while achieving high battery capacity. The fine particle size is prepared in advance through controlled precipitation and drying processes.
Solution Approach 2:
The patent changes the particle size parameter of the transition metal-containing hydroxide to 10 μm or less, which fundamentally alters the firing behavior. This parameter change allows the material to achieve complete reaction at lower temperatures, preventing phase transition and segregation of additive metal elements while maintaining high reactivity and battery capacity.
2Productivity
If the firing temperature is increased to improve battery capacity, then the reactivity improves, but the dispersion state of additive metal elements becomes nonuniform
Solution Approach 1:
The patent applies preliminary action by controlling the particle size of the transition metal-containing hydroxide precursor to 10 μm or less before firing. This pre-processing step ensures that the fine particles react more completely at lower firing temperatures (900-1000°C), preventing additive metal element segregation while achieving high battery capacity. The fine particle size is prepared in advance through controlled precipitation and drying processes.
Solution Approach 2:
The patent changes the particle size parameter of the transition metal-containing hydroxide to 10 μm or less, which fundamentally alters the firing behavior. This parameter change allows the material to achieve complete reaction at lower temperatures, preventing phase transition and segregation of additive metal elements while maintaining high reactivity and battery capacity.
3Reliability
If the firing temperature is decreased to prevent additive metal element elution, then the elution is prevented, but the battery capacity decreases
Solution Approach 1:
The patent changes the particle size parameter of the transition metal-containing hydroxide to 10 μm or less, which fundamentally alters the firing behavior. This parameter change allows the material to achieve complete reaction at lower temperatures, preventing phase transition and segregation of additive metal elements while maintaining high reactivity and battery capacity.
Solution Approach 2:
The patent applies preliminary action by controlling the particle size of the transition metal-containing hydroxide precursor to 10 μm or less before firing. This pre-processing step ensures that the fine particles react more completely at lower firing temperatures (900-1000°C), preventing additive metal element segregation while achieving high battery capacity. The fine particle size is prepared in advance through controlled precipitation and drying processes.
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 prevents additive metal element segregation during firing, enhancing battery capacity, cycle characteristics, and safety by maintaining a stable crystal structure and uniform metal distribution.
Implementation Method 1
an additive metal element that is a trace element contained in the transition metal-containing hydroxide may be eluted by phase transition or segregation
Implementation Method 2
controlled by a heat capacity obtained by differential scanning calorimetry
Data Source
AI summary
A transition metal-containing hydroxide comprising major metal element and additive metal element, wherein a value A calculated by the following formula (1) is 3.00 J/g·° C. or less: A =[S2×(X1−B1)/X2×(S1−B1)]×S3 . . . (1) wherein S1 represents a heat flow (unit: mW) at 125° C. obtained by differential scanning calorimetry of a standard substance, X1 represents a heat flow (unit: mW) at 125° C. obtained by differential scanning calorimetry of the transition metal-containing hydroxide, B1 represents a heat flow (unit: mW) at 125° C. obtained by differential scanning calorimetry of a sample container used for differential scanning calorimetry, S2 represents a mass (unit: mg) of the standard substance used for differential scanning calorimetry, X2 represents a mass (unit: mg) of the transition metal-containing hydroxide used for differential scanning calorimetry, and S3 represents a specific heat capacity (unit: J/g·° C.) of the standard substance.