Hydroxide Precursor Pore Control for Stable Cathode Metal Dispersion
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Solution Overview
Problem
Secondary batteries face issues with the elution of additive metal elements due to phase transition or segregation during calcination, leading to deteriorated cycle characteristics and safety, despite efforts to improve battery capacity.
Innovation Solution
A transition metal-containing hydroxide with controlled cumulative pore volume and particle diameter, using a specific composition and manufacturing method to prevent additive metal element segregation, ensuring excellent battery capacity and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the calcination temperature is increased to improve battery capacity, then the reactivity of the transition metal-containing hydroxide and lithium compound improves, but the additive metal element is eluted due to phase transition or segregation
Solution Approach 1:
The patent controls the cumulative pore volume parameter of the transition metal-containing hydroxide to 0.145 cm³/g or less, which fundamentally changes the material's structural parameters to prevent additive metal element elution during calcination while maintaining high battery capacity
Solution Approach 2:
The patent performs preliminary control of the cumulative pore volume before calcination to prevent phase transition or segregation of additive metal elements during the calcination process, thereby avoiding elution issues that would otherwise occur at high temperatures
2Productivity
If the calcination temperature is increased to improve battery capacity, then the reactivity improves, but the dispersion state of the additive metal element becomes nonuniform
Solution Approach 1:
By controlling the cumulative pore volume to 0.145 cm³/g or less, the patent changes the physical parameter of the hydroxide precursor to ensure uniform dispersion of additive metal elements is maintained even after high-temperature calcination
Solution Approach 2:
The patent establishes the appropriate cumulative pore volume before calcination as a preliminary measure to ensure that the additive metal elements remain uniformly dispersed throughout the positive electrode active material after calcination
3Productivity
If the additive metal element is eluted from the transition metal-containing hydroxide, then the battery capacity may be affected, but the cycle characteristics and safety of the secondary battery deteriorate
Solution Approach 1:
The patent changes the cumulative pore volume parameter to 0.145 cm³/g or less, which prevents additive metal element elution during calcination and subsequent battery operation, thereby eliminating safety hazards while preserving battery capacity
Solution Approach 2:
The patent converts the potential harm of additive metal element elution into a benefit by controlling the cumulative pore volume to prevent elution, thereby transforming a safety risk into a reliable and safe battery system
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 solution effectively prevents additive metal element segregation during calcination, enhancing the cycle characteristics and safety of secondary batteries while maintaining excellent battery capacity, even at high calcination temperatures.
Implementation Method 1
a cumulative pore volume in a BJH method measured by a gas adsorption method is 0.145 cm3/g or less
Data Source
AI summary
Provided is a transition metal-containing hydroxide capable of improving the cycle characteristics and safety of a secondary battery, while imparting an excellent battery capacity to the secondary battery, by preventing the elution of an additive metal element, which contained in the transition metal-containing hydroxide, due to phase transition or segregation.A transition metal-containing hydroxide that is a precursor of a positive electrode active material in a non-aqueous electrolyte secondary battery, the transition metal-containing hydroxide containing at least one main metal element selected from the group consisting of Ni, Co and Mn and at least one additive metal element selected from the group consisting of Mg, Ca, Sr, Ba, Ti, Zr, V, Nb, Cr, Mo, W, Fe, Ru, Cu, Zn, B, Al, Ga, Si, Sn, P and Bi, in which a cumulative pore volume in a BJH method measured by a gas adsorption method is 0.145 cm3/g or less.