Ni-rich Cathode Coated with Zr-based Layer
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Solution Overview
Problem
High-voltage lithium-ion batteries face capacity fading and safety issues due to surface structural degradation of Ni-rich LiNixCoyMnzO2 cathode materials at elevated voltages, leading to unwanted side reactions and reduced cycling stability.
Innovation Solution
A modified cathode composition featuring a Ni-rich LiNixCoyMnzO2 portion coated with LiαZrβOγ and doped with elemental metals like Zr, Si, Sn, Nb, Ta, Al, or Fe, enhancing structural stability and inhibiting side reactions, combined with advanced electrolytes such as solid-state or liquid electrolytes for improved performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If Ni-rich LiNixCoyMnzO2 cathode material is used to achieve high capacity, then discharge capacity is improved, but surface structural degradation occurs leading to capacity fading and reduced cycling stability
Solution Approach 1:
The patent applies composite materials by coating Ni-rich LiNixCoyMnzO2 cathode particles with Li2ZrO3, Li4ZrO4, Li6Zr2O7, or Li8ZrO6. This creates a composite structure where the Zr-based coating layer protects the Ni-rich cathode material from surface structural degradation while maintaining high discharge capacity, thereby improving cycling stability without sacrificing capacity
Solution Approach 2:
The patent changes the chemical composition parameters of the cathode material by doping with elemental metals (Zr, Si, Sn, Nb, Ta, Al, or Fe) and coating with Li-Zr-O compounds. These parameter changes modify the surface properties and crystal structure to enhance structural stability at high voltages, preventing capacity fading while maintaining high capacity performance
2Power
If Ni-rich LiNixCoyMnzO2 cathode material is operated at elevated voltages to improve energy density, then power output is improved, but surface structural degradation and unwanted side reactions increase
Solution Approach 1:
The patent introduces Li2ZrO3, Li4ZrO4, Li6Zr2O7, or Li8ZrO6 coating layers as intermediary protective layers between the Ni-rich cathode material and the electrolyte. These intermediary layers prevent direct contact and unwanted side reactions at elevated voltages, stabilizing the surface structure while allowing the battery to operate at high power output levels
Solution Approach 2:
The patent modifies the surface composition parameters by adding Zr-based compounds and elemental metal dopants, which change the electrochemical stability window and surface reactivity. This allows the cathode to withstand elevated operating voltages without suffering from surface structural degradation, enabling higher power output
Data Source
AI summary
A composition includes a first portion including Ni-rich LiNixCoγMnzO2, where 0.5<x<1, 0<y<1, 0<z<1; a second portion including LiαZrβOγ, where 0<α<9, 0<β<3, and 1<γ<10 such that the second portion is coated on the first portion, and the first portion is doped with an elemental metal selected from at least one of Zr, Si, Sn, Nb, Ta, Al, and Fe. A method of forming a composition includes mixing a metal precursor with nickel-cobalt-manganese (NCM) precursor to form a first mixture; adding a lithium-based compound to the first mixture to form a second mixture; and calcining the second mixture at a predetermined temperature for a predetermined time to form the composition.