Cobalt-Free Cathode Material Blending for High-Voltage Cycle Life
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing demand for large-sized, high-capacity, and high-energy-density rechargeable lithium batteries is hindered by the scarcity and high cost of cobalt, a rare metal, necessitating the development of cobalt-free or low-cobalt positive electrode active materials that maintain high capacity, energy density, and structural stability while minimizing side reactions with electrolytes.
Innovation Solution
A positive electrode active material comprising lithium nickel-manganese-based composite oxides with specific particle sizes and a combination of lithium transition metal phosphate, formulated to exclude cobalt or minimize its content, and coated with aluminum and zirconium to enhance structural stability and suppress electrolyte reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If cobalt is used in positive electrode active materials to achieve high capacity and high energy density, then battery performance is improved, but production cost increases and material availability becomes limited
Solution Approach 1:
The patent removes cobalt from the positive electrode active material composition entirely, using only nickel and manganese in a lithium nickel-manganese composite oxide structure. This extraction of the problematic element (cobalt) eliminates the cost and availability issues while maintaining the desired high capacity through optimized nickel content (≥60 mol%) and appropriate manganese content for structural stability.
2Quantity of substance
If nickel content is increased to achieve high capacity, then energy density is improved, but side reactions with electrolyte at high voltage increase
Solution Approach 1:
The patent optimizes the compositional parameters by setting nickel content to ≥60 mol% while controlling manganese content to provide structural stability. This parameter optimization allows high capacity while the specific stoichiometric ratios prevent excessive side reactions with electrolyte at high voltage by balancing the reactive nickel with stabilizing manganese.
Solution Approach 2:
The patent creates a composite lithium nickel-manganese oxide material where nickel provides high capacity and manganese provides structural stability and reduced electrolyte reactivity. The synergistic combination in a single-phase composite structure allows the benefits of high nickel content while mitigating its harmful side reactions with electrolyte through the stabilizing effect of manganese.
3Ease of manufacture
If cobalt-free materials are used to reduce cost, then production cost decreases, but achieving high capacity and long cycle-life becomes more difficult
Solution Approach 1:
The patent achieves long cycle-life in cobalt-free materials by precisely controlling the compositional parameters: nickel content ≥60 mol% for high capacity, with manganese content optimized to maintain structural stability during cycling. This parameter optimization ensures that the cobalt-free lithium nickel-manganese composite oxide maintains both economic advantage and reliable long-term cycling performance.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A positive electrode active material including a first positive electrode active material including a lithium nickel-manganese-based composite oxide having a nickel content of greater than or equal to about 60 mol% based on about 100 mol% of a total metal excluding lithium and including secondary particles made by agglomerating a plurality of primary particles wherein an average particle diameter (D50) of the secondary particle is about 10 µm to about 20 µm, a second positive electrode active material including a lithium nickel-manganese-based composite oxide having a nickel content of greater than or equal to about 60 mol% based on about 100 mol% of a total metal excluding lithium and including single particles wherein an average particle diameter (D50) of each of the single particles is about 2 µm to about 8 µm, and a third positive electrode active material including particles including lithium transition metal phosphate.