High-Nickel Cathode Material Processing for Longer Cycle Life
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cathode active materials for lithium-ion batteries, such as LiNiO2, suffer from poor cycle life, pronounced gassing, and increased internal resistance during cycling, limiting their commercial application.
Innovation Solution
A process involving the preparation of an (oxy)hydroxide of transition metals with high nickel content, followed by mixing with a lithium source and compounds of Mg or Al, and subsequent thermal treatment at specific temperatures to form a cathode active material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If high nickel content (at least 80 mol-%) is used in the transition metal oxide to improve charge density and specific energy, then battery energy density is improved, but cycle life deteriorates and internal resistance increases
Solution Approach 1:
The patent uses a composite material system consisting of lithium transition metal oxide (with at least 80 mol-% nickel) combined with magnesium oxide and aluminum oxide. This composite structure allows the high-nickel material to provide high charge density while the MgO and AlOx components mitigate the deterioration of cycle life and internal resistance, resolving the contradiction between energy density and reliability.
2Quantity of substance
If high nickel content (at least 80 mol-%) is used to improve specific energy, then battery energy capacity is improved, but gassing increases and internal resistance increases
Solution Approach 1:
The composite material system of lithium nickel oxide with MgO and AlOx additives suppresses the harmful gassing effect while maintaining high specific energy. The MgO and AlOx components act as stabilizers that prevent the excessive gassing that would otherwise occur with high-nickel content materials.
3Ease of manufacture
If conventional thermal treatment at 600 to 1000° C. is used to form the electrode active material, then the material is formed through solid state reaction, but capacity loss increases and cycle life decreases
Solution Approach 1:
The patent applies parameter changes by conducting thermal treatment at a lower temperature range (400 to 700° C.) compared to conventional methods (600 to 1000° C.). This temperature reduction, combined with the specific composition ratios of lithium source (75 to 85 mol-%) and the addition of MgO and AlOx, modifies the solid state reaction process to reduce capacity loss and improve cycle life while still forming the electrode active material.
4Productivity
If conventional calcination at high temperatures (600 to 1000° C.) is performed to form the cathode material, then the electrode active material is obtained, but internal resistance strongly increases during cycling
Solution Approach 1:
The patent changes the thermal treatment temperature parameter to 400 to 700° C., which is lower than conventional calcination temperatures. This parameter change, combined with the specific composition (high nickel content with MgO and AlOx additives), prevents the strong increase in internal resistance that occurs with conventional high-temperature processing, while still enabling efficient material production.
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 resulting cathode active material exhibits improved charge density, specific energy, and reduced capacity loss, leading to enhanced battery performance and longevity.
Implementation Method 1
treating the resultant mixture at a temperature at a temperature in the range of from 400 to 700° C.
Implementation Method 2
During the thermal treatment a solid state reaction takes place, and the electrode active material is formed
Implementation Method 3
In cases hydroxides or carbonates are used as precursors the solid state reaction follows a removal of water or carbon dioxide
Data Source
AI summary
Disclosed herein is a process for making an electrode active material. The process includes the following steps:(a) providing an (oxy)hydroxide of TM, where TM is a transition metal and includes nickel and, optionally, at least one of cobalt and manganese,(b) mixing the (oxy)hydroxide of TM with 75 to 85 mol-% of a lithium source, referring to TM, and at least one compound of Mg or Al,(c) treating the resultant mixture at a temperature in the range of from 400 to 700° C., thereby obtaining a powder,(d) mixing the powder from step (c) with a source of lithium and with at least one compound of Mg or Al and with at least one compound of Nb, Ta, W, Ti or Zr, and(e) treating the mixture obtained from step (d) thermally at a temperature in the range of from 550 to 800° C.