High-Entropy Doped Cathode Material for Capacity-Stable Ni-Rich Cells
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Solution Overview
Problem
Traditional doping methods for high-nickel ternary positive electrode materials improve cycle stability but decrease specific capacity, making it difficult to achieve both high cycle stability and specific capacity simultaneously.
Innovation Solution
A high entropy doped positive electrode material, represented by LiNi x Co y Mn z B a M b O 2, is developed, where M comprises multiple elements like Al, Zr, Sr, Sn, Sb, Si, Ba, Y, W, Ta, Ti, Mo, Nb, La, and Ce, with B being dominant, adsorbed on the (003) crystal plane to refine primary particle size and enhance electrochemical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional doping methods are used to improve cycle stability of high-nickel positive electrode materials, then cycle stability is improved, but specific capacity decreases
Solution Approach 1:
The patent employs high-entropy doping by incorporating five or more different elements (such as Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Te, Bi) into the positive electrode material lattice. This multi-element composite approach creates a complex solid solution that simultaneously improves cycle stability through lattice strengthening and maintains high specific capacity by optimizing electronic structure and ion transport pathways, thereby resolving the trade-off between reliability and quantity of substance.
Solution Approach 2:
The patent systematically varies the composition parameters of the doping elements, controlling the atomic ratios and concentration ranges of each element in the high-entropy doping system. By precisely adjusting these compositional parameters within specific ranges, the material achieves optimal balance between structural stability (improving cycle life) and electrochemical activity (maintaining capacity), thus resolving the contradiction through parameter optimization.
2Use of energy by moving object
If Ni content is increased to achieve high energy density, then energy density is improved, but chemical performance decay and oxygen escape are aggravated
Solution Approach 1:
The patent applies high-entropy doping to create local compositional variations within the nickel-rich lattice structure. The multiple doping elements are distributed at specific lattice sites, creating local regions with different chemical environments that stabilize the overall structure. This local quality modification allows high Ni content (for energy density) while preventing harmful effects like oxygen escape and chemical decay through localized structural reinforcement.
Solution Approach 2:
The doping elements in the high-entropy system act as intermediaries between the nickel atoms and the crystal lattice structure. These intermediary elements buffer the structural stress caused by high nickel content, mediate oxygen stability, and prevent direct degradation pathways. The multiple doping elements collectively serve as structural mediators that enable high energy density while maintaining chemical performance 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 high entropy doped positive electrode material exhibits both high specific capacity and cycle stability, with improved mechanical stability and electrochemical performance due to synergistic effects from multiple doping elements.
Implementation Method 1
B being dominant, adsorbed on the (003) crystal plane to refine primary particle size and enhance electrochemical performance
Data Source
Figure 1~2
Figure 3
AI summary
The present application relates to a high entropy doped positive electrode material and production method and use thereof. The high entropy doped positive electrode material of the present application comprises a material represented by a chemical formula of LiNixCoyMnzBaMbO2, wherein 0.80≤x<0.98, 0<y<0.2, 0<z<0.2, a>0, b>0, a≥b, x+y+z+a+b=1, and M comprises at least four of Al, Zr, Sr, Sn, Sb, Si, Ba, Y, W, Ta, Ti, Mo, Nb, La, Ta and Ce. The high entropy doped positive electrode material of the present application can have both high specific capacity and cycle stability.