Lithium-Manganese-Rich Cathode Blend for High-Density Li-Ion Batteries
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Solution Overview
Problem
The increasing demand for large-sized, high-capacity, or high-energy-density rechargeable lithium batteries poses a challenge due to the limited supply and high cost of cobalt, a rare metal used in traditional positive electrode active materials.
Innovation Solution
A lithium-manganese-rich positive electrode active material is developed, comprising a mixture of first and second lithium-manganese-rich composite oxides with specific molar ratios of lithium to total metal excluding lithium and manganese content, which improves bulk density and cycle-life characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cobalt-containing positive electrode active materials are used, then high capacity and good cycle-life characteristics are achieved, but production cost increases and resource availability decreases
Solution Approach 1:
The invention extracts cobalt from the positive electrode active material composition, developing cobalt-free lithium-manganese-rich composite oxides. This eliminates dependence on scarce and expensive cobalt while maintaining electrochemical performance through optimized lithium-manganese-stabilized structures with controlled doping elements.
Solution Approach 2:
The invention changes the compositional parameters by precisely controlling the molar ratio of lithium to total metal (excluding lithium) within 1.06-1.20 and manganese content at ≥30 mol%, along with controlled doping of nickel, cobalt (≤10 mol%), and aluminum. These parameter optimizations maintain high capacity and cycle-life characteristics without requiring high cobalt content.
2Quantity of substance
If lithium-manganese-rich composite oxide with high manganese content is used, then capacity is increased, but bulk density decreases
Solution Approach 1:
The invention applies local quality optimization by creating a core-shell structure where the inner core contains high-manganese lithium-manganese-rich composite oxide for high capacity, while the outer shell or surface regions incorporate stabilized structures with controlled doping to improve particle packing and bulk density. This spatial differentiation allows simultaneous achievement of high capacity and improved density.
Solution Approach 2:
The invention uses composite materials by combining lithium-manganese-rich composite oxide with controlled amounts of doping elements (nickel, cobalt, aluminum) to create a multi-phase composite structure. This composite approach maintains the high capacity benefits of high manganese content while the dopants improve structural stability and particle morphology for better bulk density.
3Ease of manufacture
If cobalt content is reduced or eliminated, then production cost decreases and resource availability improves, but capacity and cycle-life characteristics may deteriorate
Solution Approach 1:
The invention replaces expensive cobalt with cheaper manganese-based materials, using abundant and cost-effective resources. The lithium-manganese-rich composite oxide with controlled doping provides an economical alternative that maintains acceptable performance levels while significantly reducing material costs and eliminating dependence on scarce cobalt resources.
Solution Approach 2:
The invention changes the compositional parameters by precisely controlling the molar ratio of lithium to total metal within 1.06-1.20 and manganese content at ≥30 mol%, along with controlled doping of nickel, cobalt (≤10 mol%), and aluminum. These parameter optimizations maintain high capacity and cycle-life characteristics without requiring high cobalt content.
Data Source
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AI summary
Disclosed are a positive electrode active material, and a rechargeable lithium battery, the positive electrode active material including a first positive electrode active material including a first lithium-manganese-rich composite oxide in which a molar ratio of lithium to a total metal excluding lithium is about 1.06 to about 1.2 and a manganese content based on 100 mol% of a total metal excluding lithium is greater than or equal to about 30 mol%, and a second positive electrode active material including a second lithium-manganese-rich composite oxide in which a molar ratio of lithium to a total metal excluding lithium is greater than about 1.2 and less than or equal to about 2 and a manganese content based on 100 mol% of a total metal excluding lithium is greater than or equal to about 30 mol%, and having an average particle diameter (D50) smaller than an average particle diameter (D50) of the first positive electrode active material.