Lithium Complex Oxide Electrode Material for Battery Capacity and Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium complex oxides for non-aqueous electrolyte secondary batteries, particularly those containing molybdenum, face limitations in charge and discharge characteristics, thermal stability, and cost-effectiveness, necessitating the development of a novel lithium complex oxide with improved performance.
Innovation Solution
A lithium complex oxide with a specific compositional formula (Li x M y Mo z O) where M is Ni, Mn, or Co, and x, y, z are within defined ranges, exhibiting a rock-salt, Li 5 ReO 6-, Li 4 MoO 5-, or Li 2 MnO 3-type crystal structure, and an average valence of Mo between 5.7 and 6.0, enhancing charge and discharge capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional lithium complex oxides (e.g., LiCoO2, Li4MoO5) are used as positive electrode active materials, then the battery can achieve basic charge and discharge functionality, but the charge and discharge characteristics and battery capacity are limited
Solution Approach 1:
The invention changes the chemical composition parameters by introducing multi-element doping (Ni, Mn, Fe, Co) with specific atomic ratios (0.1≤x≤2.3, 0.05≤y≤0.50, 0.05≤z≤0.50) and controlling the average oxidation state of Mo (5.0-6.0). This parameter optimization resolves the contradiction by achieving both high battery capacity (up to 280 mAh/g) and excellent charge-discharge characteristics (retaining 80% capacity after 50 cycles) simultaneously.
Solution Approach 2:
The invention creates a composite lithium complex oxide material Li x M y Mo z O 3-y/2-w/2 with multiple transition metals (M=Ni, Mn, Fe, Co) combined with molybdenum. This composite structure integrates the advantages of different metals: Ni and Co provide high capacity, Mn enhances stability, and Mo contributes to voltage. The synergistic effect resolves the contradiction between capacity and reliability by combining materials with complementary properties.
2Productivity
If high-capacity materials are developed to surpass LiCoO2, then battery capacity increases, but thermal stability in charged state may be compromised
Solution Approach 1:
The invention applies local quality by creating a multi-element doped structure where different metal elements are distributed at specific lattice positions. The Mo atoms with high oxidation states (5.0-6.0) are strategically positioned to provide thermal stability, while Ni and Co atoms contribute to high capacity. This localized functional distribution resolves the contradiction between high capacity and thermal stability.
Solution Approach 2:
The invention provides beforehand cushioning by incorporating Mn and Fe elements that act as structural stabilizers before thermal degradation can occur. These elements form a stable crystal framework that prevents catastrophic failure during thermal stress, allowing the battery to maintain both high capacity and thermal stability in the charged state.
3Use of energy by moving object
If molybdenum-based materials are used to increase voltage and energy density, then battery performance improves, but the cost increases due to material complexity
Solution Approach 1:
The invention applies universality by using the Li x M y Mo z O 3-y/2-w/2 composition framework that can accommodate multiple transition metals (Ni, Mn, Fe, Co) in various ratios. This universal structure achieves high energy density (voltage up to 4.0V) while allowing flexibility in material selection based on cost considerations. The multi-functional design allows optimization of both performance and manufacturing cost.
4Reliability
If existing lithium molybdate structures (e.g., Li4MoO5) are used, then the material shows good electrochemical performance, but the charge and discharge characteristics and conductivity are insufficient
Solution Approach 1:
The invention changes the electrochemical parameters by optimizing the Mo oxidation state (5.0-6.0) and the stoichiometric ratios of metal elements. This parameter control enhances both the electrochemical performance (voltage 3.8-4.0V) and the charge-discharge characteristics (improved conductivity and reaction kinetics), resolving the contradiction between reliability and productivity.
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 novel lithium complex oxide demonstrates improved charge and discharge characteristics, thermal stability, and cost-effectiveness, surpassing the performance of existing Li 4 MoO 5, with enhanced battery capacity and conductivity through strategic doping and crystal structure optimization.
Implementation Method 1
an average valence of Mo is 5.7 to 6.0
Data Source
Figure 1~3
Figure 4
Figure 5~6
AI summary
Provided is a novel lithium complex oxide containing molybdenum. A complex oxide represented by the following compositional formula: LixMyMozO wherein M is one or two or more selected from the group consisting of Mn, Ru, Sn, Mg, Al, Ti, V, Cr, Fe, Co, Ni, Cu, and Zn; x is in the range of 0.60 to 0.75; y is in the range of 0.15 to 0.25; and z is in the range of 0.075 to 0.20.