Cathode Electrode Processing with Controlled Particle Cracking
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Solution Overview
Problem
Lithium-ion batteries face issues with capacity fade and reduced cycling stability due to crack formation in cathode active materials, which existing solutions have not adequately addressed.
Innovation Solution
A process involving the use of lithiated transition metal oxides with specific compositions and particle sizes, mixed with conductive carbon and subjected to high pressure to create cracks, followed by incorporation with a binder and solvent, and application to a metal foil to enhance electrode stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional thermal treatment methods are used to form electrode active material, then the material can be produced through standard manufacturing processes, but crack formation occurs in the particles leading to capacity fade and reduced cycling stability
Solution Approach 1:
The patent applies preliminary action by subjecting the electrode active material particles to high pressure (100-500 MPa) before electrode manufacturing to pre-form cracks and densify the particle structure. This preliminary densification prevents further crack formation during subsequent electrode processing and battery cycling, thereby improving cycling stability while controlling the harmful crack formation effect.
2Stability of the object's composition
If high pressure is applied to densify particle structure, then particle density and electrode stability improve, but the process complexity and manufacturing difficulty increase
Solution Approach 1:
The patent applies parameter changes by optimizing the pressure range to 100-500 MPa and treatment time to 1-60 seconds, achieving effective particle densification without excessive process complexity. This controlled parameter approach enables the beneficial effects of high-pressure treatment while maintaining manufacturing feasibility.
3Reliability
If particle density is increased through high pressure treatment, then cycling stability improves, but the treatment time and energy consumption increase
Solution Approach 1:
The patent optimizes the treatment parameters by limiting pressure to 100-500 MPa and time to 1-60 seconds, achieving effective particle densification and improved cycling stability within a reasonable time frame. This parameter optimization balances the benefits of densification with the costs of treatment time and energy consumption.
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 process results in electrodes with reduced capacity fade and improved cycling stability, effectively addressing the limitations of previous methods by creating a stable electrode structure through controlled crack formation and material composition.
Implementation Method 1
exposing the mixture obtained in step (b) to a pressure in the range of from 100 to 500 MPa over a period of time of from one second to one minute, thereby causing cracks in at least some of the particles of the electrode active material
Implementation Method 2
mixing the lithiated transition metal oxide from step (a) with carbon in electrically conductive form
Implementation Method 3
mixing the mixture from step (c) with a binder polymer
Data Source
Figure 1a~1c
AI summary
The present invention is directed towards a process for making an electrode wherein the process comprises the following steps (a) providing a particulate lithiated transition metal oxide according to the formula Li1+xTM1-xO2 wherein x is in the range of from zero to 0.1 and TM contains nickel and at least one of Co, Mn and Al, (b) mixing the lithiated transition metal oxide from step (a) with carbon in electrically conductive form, (c) exposing the mixture obtained in step (b) to a pressure in the range of from 100 to 500 MPa over a period of time of from one second to one minute, thereby causing cracks in at least some of the particles of the electrode active material, (d) mixing the mixture from step (c) with a binder polymer and, optionally, with further carbon in electrically conductive form and with a solvent, (e) applying the mixture from step (d) to a metal foil.