Gradient-Doped Cathode Precursor for Stable High-Nickel Batteries
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Solution Overview
Problem
High-nickel positive electrode materials face issues with short cycle life, low thermal stability, and insufficient chemical stability, which hinder their potential as promising materials for next-generation lithium-ion batteries.
Innovation Solution
A multi-element doped positive electrode precursor is developed, featuring N doped layers with specific doping elements, including W and Al, to enhance structural stability and thermal stability, and a solution co-precipitation method is used for preparation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If high-nickel positive electrode materials are used to achieve high energy storage capability, then discharge specific capacity is improved, but cycle life becomes short
Solution Approach 1:
The precursor is divided into multiple doped layers (first doped layer to Nth doped layer) with different doping elements, where each layer has a specific function. The inner layers use elements like W, Mo, Zr, Ti for structural stability, while outer layers use elements like Al for surface protection, creating a segmented structure that simultaneously addresses capacity and cycle life
Solution Approach 2:
Different doping elements are selectively placed in different regions of the precursor. The doping elements are arranged in a gradient manner from inside to outside, with specific elements concentrated in specific layers to provide localized functions - inner layers provide structural framework stability while outer layers provide surface protection and oxygen binding
2Use of energy by moving object
If high-nickel positive electrode materials are used to achieve high energy storage capability, then discharge specific capacity is improved, but thermal stability becomes low
Solution Approach 1:
Doping elements are introduced into the precursor structure before the final material formation. This preliminary doping action creates a stable framework and surface protection in advance, preventing thermal degradation during subsequent battery operation and charging/discharging cycles
Solution Approach 2:
The precursor is designed as a composite structure combining nickel-based main material with multiple doping elements (W, Mo, Zr, Ti, Al, etc.) in different layers. This composite structure integrates the high capacity of nickel with the thermal stability and structural strength of doping elements
3Use of energy by moving object
If high-nickel positive electrode materials are used to achieve high energy storage capability, then discharge specific capacity is improved, but chemical stability becomes insufficient
Solution Approach 1:
The precursor is divided into multiple doped layers (first doped layer to Nth doped layer) with different doping elements, where each layer has a specific function. The inner layers use elements like W, Mo, Zr, Ti for structural stability, while outer layers use elements like Al for surface protection, creating a segmented structure that simultaneously addresses capacity and cycle life
Solution Approach 2:
Different doping elements are selectively placed in different regions of the precursor. The doping elements are arranged in a gradient manner from inside to outside, with specific elements concentrated in specific layers to provide localized functions - inner layers provide structural framework stability while outer layers provide surface protection and oxygen binding
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 multi-element doped precursor improves cycle stability and thermal stability, with Al doping stabilizing the structure and enhancing oxygen binding to inhibit lattice oxygen loss, while maintaining high capacity and cycle performance.
Implementation Method 1
Al doping stabilizing the structure and enhancing oxygen binding to inhibit lattice oxygen loss
Implementation Method 2
performing a solution co-precipitation reaction so as to render the multi-element doped positive electrode precursor
Data Source
Figure 1~2
Figure 3a~3b
Figure 4a~5
AI summary
The present application provides a multi-element doped positive electrode precursor and a preparation method therefor, a positive electrode material, a battery and an electrical device, relating to the field of batteries. The multi-element doped positive electrode precursor includes N doped layers, which are a first doped layer to an Nth doped layer respectively from inside to outside, a doping element W is doped in each doped layer, and a doping element Al is doped in the Nth doped layer, N being a natural number greater than or equal to 2. A preparation method for the multi-element doped positive electrode precursor includes: adding a raw material including a metal salt solution, a precipitant and a complexing agent into a base solution, and performing a solution co-precipitation reaction so as to render the multi-element doped positive electrode precursor. For the multi-element doped positive electrode precursor provided in the present application, the number of doping elements is increased and distributed in a gradient from inside to outside, and the multi-element doping can reduce polarization, greatly reduce volume change, and enhance thermal stability, chemical stability and cycle performance of the positive electrode material.