Tungsten-Doped Multi-Ionic Cathode for Stable High-Capacity Cycling
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Solution Overview
Problem
Existing cathode materials for rechargeable batteries, particularly layered transition metal oxides, face challenges in delivering high specific capacity with minimal fading on cycling while maintaining cost-effectiveness.
Innovation Solution
A tungsten-doped mixed cation cathode active material with a novel anionic stoichiometry is developed, featuring a layered transition metal oxide structure, which includes alkali metals and transition metals, enhancing structural stability and ion movement through enlarged interlayer spacing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional layered transition metal oxide cathode materials are used, then the battery can achieve adequate energy storage, but the specific capacity is limited and capacity fading occurs during cycling
Solution Approach 1:
The patent modifies the chemical composition parameters of the cathode material by introducing tungsten doping and adjusting the ratio of transition metals (Ni, Co, Mn) to achieve higher specific capacity and reduced capacity fading. The formula Li1-a-bM1xbM21-x-cM3cWbO2 allows systematic variation of compositional parameters to optimize performance
Solution Approach 2:
The patent creates a composite cathode material by combining multiple transition metals (Ni, Co, Mn) with tungsten dopant in a layered oxide structure. This multi-element composite approach leverages the complementary properties of each element to achieve both high capacity and cycling stability
2Reliability
If the interlayer spacing is increased to improve ion diffusion, then the cycling stability improves, but the structural integrity may be compromised
Solution Approach 1:
The patent applies local quality modification by introducing tungsten atoms at specific positions within the layered structure. The tungsten dopant locally reinforces the structure while the overall interlayer spacing is expanded, creating different functional zones within the material structure
Solution Approach 2:
The tungsten dopant acts as a structural cushioning element that prevents excessive structural degradation during cycling. By incorporating W into the lattice beforehand, the material is pre-stabilized against the mechanical stress and phase transitions that occur during charge-discharge cycles
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 tungsten-doped cathode material exhibits improved specific capacity, ranging from 130 to 150 mAh/g, with minimal capacity fading, thereby increasing the energy density of energy storage devices.
Implementation Method 1
Metal doping is proven to be an important and reliable approach to stabilize the interslab spaces, reduce multiple phase transitions
Implementation Method 2
Layered transition metal oxides have attractive properties as cathode materials for rechargeable batteries, such as the ease of synthesis and the high feasibility and reversibility of the sodium shuttling process
Data Source
AI summary
The present invention discloses to tungsten doped mixed cationic cathodes for energy devices notably non-aqueous re-chargeable alkali-ion electrochemical cells and batteries and to the process of preparation thereof. More particularly, the present invention discloses to doped cathode active materials of Formula (I) that show a higher capacity and which can able to retains their structure during the entire charging-discharging cycles.