M-Ion Doped Cathode Composition to Limit Lithium-Nickel Mixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lithium-ion battery cathode electrode materials, such as LiNiO3 and ternary lithium nickel cobalt manganate, suffer from poor cycle life and thermal stability, posing safety hazards and not meeting the requirements for long mileage and safety in electric vehicles.
Innovation Solution
A cathode electrode material with a formula LiaNi1-x-y-zCoxMnyAlzMbO2, doped with ions like B, Zr, Al, Ti, Mg, Na, Ca, Nb, Ba, Si, P, W, and Sr, which reduces divalent nickel ion content and lithium-nickel mixing, stabilizing the crystal structure and improving cycle retention and thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If nickel content is increased in cathode electrode material, then battery capacity is improved, but cycle life and thermal stability deteriorate
Solution Approach 1:
The patent applies local quality by creating a dual-doped structure where M elements (such as Al, Ti, Mg) are selectively introduced into specific lattice positions to stabilize the crystal structure, while B elements are used for surface coating to protect the bulk material. This localized modification allows the bulk to maintain high nickel content for capacity while the surface and critical lattice positions provide structural stability for long cycle life.
Solution Approach 2:
The patent employs composite materials by combining multiple doping elements (M elements + B elements) to create a composite cathode material structure. The M elements (Al, Ti, Mg, etc.) are doped into the bulk lattice to stabilize the layered structure, while B elements form a protective surface coating layer. This composite approach synergistically combines the high capacity benefit of high-nickel materials with the stability benefits of multiple protective elements.
2Use of energy by moving object
If nickel content is increased in cathode electrode material, then battery capacity is improved, but safety performance deteriorates
Solution Approach 1:
The patent applies beforehand cushioning by pre-stabilizing the crystal structure through M element doping before any degradation can occur during battery operation. The M elements (Al, Ti, Mg) are incorporated into the lattice to prevent structural collapse and reduce oxygen release tendencies that would otherwise occur in high-nickel materials during cycling and thermal events, thereby cushioning against future safety hazards.
Solution Approach 2:
The patent uses a thin film approach by applying a B element surface coating layer that acts as a protective shell. This thin film barrier prevents direct contact between the high-nickel bulk material and the electrolyte, reducing side reactions and preventing thermal runaway propagation, thereby improving safety without compromising the high-capacity benefits of the nickel-rich bulk structure.
3Stability of the object's composition
If M element doping is applied to cathode electrode material, then crystal structure stability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-mixing all doping elements (M elements and B elements) with the nickel-based precursor materials before the single-step calcination process. This preliminary mixing ensures uniform distribution of dopants throughout the precursor mixture, allowing the complex dual-doped structure to form in one sintering step rather than requiring multiple sequential doping operations, thereby simplifying manufacturing while achieving the desired crystal structure stability.
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 doped cathode electrode material exhibits enhanced cycle retention rate, thermal stability, and safety, prolonging service life and reducing potential safety hazards, making it suitable for electric vehicles with long mileage requirements.
Implementation Method 1
the cathode electrode material is doped with an M ion. Through the doping of the M ion, the content of the divalent nickel ion may be reduced
Data Source
AI summary
Disclosed are a cathode electrode material and a preparation method and application thereof. A general formula thereof is LiaNi1-x-y-zCoxMnyAlzMbO2, herein 1.04≤a≤1.08, 0.04≤x≤0.08, 0.025≤y≤0.06, 0.03≤z≤0.09, 0.015≤b≤0.06, and M is B and at least one selected from Zr, Al, Ti, Mg, Na, Ca, Nb, Ba, Si, P, W, and Sr. Compared with an existing nickel-cobalt-manganese-aluminum cathode electrode material, the cathode electrode material is doped with an M ion. Through the doping of the M ion, the content of a divalent nickel ion may be reduced, thereby the amount of the nickel ions that transit from a crystal plane (003) to a crystal plane (104) is reduced, and the degree of lithium-nickel mixing is reduced, so that the crystal structure of the cathode electrode material is stabilized, thereby the cycle retention rate and thermal stability of the material are improved, as to prolong service life of the material and improve the safety thereof.