LiNiO2 Precursor Doping for Battery Stability and Gas Suppression
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Solution Overview
Problem
Current lithium secondary batteries face challenges with high production costs, swelling due to gas generation, low chemical stability, and poor cycle characteristics in LiNiO2-based positive electrode active materials, which are not adequately addressed by surface treatments like LiF or Li2SO4 application.
Innovation Solution
A precursor of transition metal oxide with a specific chemical formula, including zirconium and a particular anion, is used to create a composite lithium and transition metal oxide, which is calcined with a lithium compound to produce a positive electrode active material with improved stability and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If LiNiO2-based positive electrode active material is used, then high discharging capacity and energy density are achieved, but production cost increases, swelling occurs due to gas generation, chemical stability decreases, and cycle characteristics worsen
Solution Approach 1:
The patent applies different elements (Zr, W, Nb, Al, Cu, Fe, Mg, B, Cr) at specific substitution ratios (0.01≤y≤0.7) to local positions in the LiNiO2 crystal structure, creating regions with enhanced stability while preserving high capacity. This local modification allows the material to maintain high discharging capacity (200 mAh/g) while improving chemical stability through targeted elemental substitution at metal sites.
Solution Approach 2:
The patent creates a composite structure by substituting nickel with multiple transition metals (Co, Mn, Zr, W, Nb, Al, Cu, Fe, Mg, B, Cr) simultaneously. This multi-element composite approach in the spinel structure (Li1+zNibMncCo1-(b+c+d)MdO(2-e)Ne) combines the benefits of different elements: Ni provides high capacity, while Co, Mn, and other dopants provide structural stability and suppress gas generation, resolving the contradiction between capacity and stability.
2Power
If LiNiO2-based positive electrode active material is used, then high discharging capacity is achieved, but production cost increases
Solution Approach 1:
The patent optimizes the composition parameters (stoichiometric ratios of Li, Ni, Co, Mn, and dopant elements) and synthesis parameters (calcination temperature, atmosphere, and time) to achieve high capacity performance. By controlling the substitution ratio (0.01≤y≤0.7) and using cost-effective dopants like Mn and Co in optimized proportions, the patent reduces reliance on expensive materials while maintaining high discharging capacity through precise compositional control.
3Power
If LiNiO2-based positive electrode active material is used, then high discharging capacity is achieved, but swelling occurs due to gas generation
Solution Approach 1:
The patent introduces stabilizing elements (Zr, W, Nb, Al, Cu, Fe, Mg, B, Cr) at specific substitution ratios to local regions of the crystal structure, creating stable zones that prevent oxygen release and gas generation during charging/discharging cycles. This local stabilization suppresses the harmful gas generation effect while preserving the high capacity characteristics of LiNiO2.
Solution Approach 2:
The patent performs preliminary doping with stabilizing elements before the battery operation begins. These pre-introduced elements (particularly O2- ions and transition metals) create a stable crystal structure that proactively prevents oxygen evolution and gas generation during subsequent high-voltage charging, countering the harmful effect before it occurs.
4Power
If LiNiO2-based positive electrode active material is used, then high discharging capacity is achieved, but cycle characteristics worsen
Solution Approach 1:
The patent introduces stabilizing elements at specific substitution ratios (0.01≤y≤0.7) to create locally stable regions within the crystal structure. These doped elements (particularly Co, Mn, Zr, and other transition metals) strengthen the crystal lattice at critical positions, preventing structural degradation during repeated cycling while maintaining the high capacity pathways provided by the Ni-rich regions.
Solution Approach 2:
The patent creates a composite spinel structure (Li1+zNibMncCo1-(b+c+d)MdO(2-e)Ne) that combines multiple elements with complementary functions: Ni provides high capacity, while Co, Mn, and dopant elements provide structural stability and suppress degradation. This composite approach enables the material to maintain both high discharging capacity (200 mAh/g) and good cycle characteristics through synergistic element interactions.
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 results in a secondary battery with reduced resistance, high output, and superior life characteristics, eliminating the need for extra surface treatment processes and enhancing charging/discharging efficiency.
Implementation Method 1
a composite of lithium and transition metal oxide, and a positive electrode and a secondary battery comprising the same
Data Source
AI summary
Provided is a precursor of transition metal oxide represented by chemical formula 1 below.NiaMnbCo1-(a+b+c+d)ZrcMd[OH(1-x)2-y]A(y/n) [Chemical formula 1]