High Nickel Cathode Material Soluble Base Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing high Z lithium transition metal oxide cathode materials for lithium-ion batteries face challenges in achieving good quality with low soluble base content and low production costs, while maintaining performance and stability, especially when using technical grade precursor materials and sintering in air.
Innovation Solution
A method involving the use of technical grade lithium carbonate and mixed transition metal hydroxides as precursors, sintered under a forced flow of air at specific temperatures and times, to achieve lithium transition metal oxide powders with a controlled soluble base content, optimized for equilibrium values, which are free of lithium carbonate and lithium hydroxide impurities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If technical grade lithium carbonate and mixed transition metal hydroxides are used as precursors, then production cost is reduced, but soluble base content increases
Solution Approach 1:
The patent applies preliminary action by conducting a pre-sintering treatment at 600-800°C for 5-20 hours under air flow before the final sintering step. This preliminary treatment removes carbonates and hydroxides from the precursor materials, preventing them from contaminating the final product. By performing this purification step beforehand, the patent enables the use of low-cost technical grade precursors while maintaining low soluble base content in the final cathode material.
2Stability of the object's composition
If sintering is performed under air flow, then air stability is improved, but soluble base content increases due to carbonate formation
Solution Approach 1:
The patent applies continuity of useful action by maintaining a forced air flow throughout the entire sintering process at temperatures above 700°C. This continuous air flow prevents carbonate formation by removing CO2 from the reaction zone and maintaining oxidative conditions that stabilize the cathode material. The process combines continuous air flow with extended sintering time (20-48 hours) to simultaneously achieve air stability and low soluble base content without requiring inert atmospheres.
3Quantity of substance
If high nickel content is used, then capacity is increased, but stability and soluble base content worsen
Solution Approach 1:
The patent applies parameter changes by optimizing the nickel content within a specific range (0.35 ≤ x < 0.50) rather than using maximum nickel content. This controlled parameter adjustment balances capacity and stability. Additionally, the patent modifies processing parameters including sintering temperature (700-900°C), time (20-48 hours), and air flow rate (1-10 L/min) to achieve low soluble base content (<100 μmol/g) in high-nickel materials, thereby improving stability while maintaining high capacity.
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
This approach enables the production of high Z lithium transition metal oxide cathode materials with improved stability, performance, and reduced production costs, maintaining a balanced soluble base content that enhances energy density and cycle stability without compromising air stability.
Implementation Method 1
a method involving the use of technical grade lithium carbonate and mixed transition metal hydroxides as precursors, sintered under a forced flow of air at specific temperatures and times
Implementation Method 2
sintered under a forced flow of air at specific temperatures and times
Data Source
AI summary
The invention relates to cathode materials for Li-ion batteries in the quaternary phase diagram Li[Li1/3Mn2/3]O2—LiMn1/2Ni1/2O2—LiNiO2—LiCoO2, and having a high nickel content. Also a method to manufacture these materials is disclosed. The cathode material has a general formula Lia ((Niz(Ni1/2Mn1/2)yCox)1−kAk)2−aO2, wherein x+y+z=1, 0.1≦x≦0.4, 0.36≦z≦0.50, A is a dopant, 0≦k≦0.1, and 0.95≦a≦1.05, and having a soluble base content (SBC) within 10% of the equilibrium soluble base content.