Negative Electrode Pre-Lithiation with Zoned Roll-to-Roll Charging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for pre-lithiating negative electrodes in a roll-to-roll process face challenges with non-uniformity and instability due to equipment shaking, leading to incomplete lithium distribution and potential precipitation on bare parts, which affects battery capacity and cycle life.
Innovation Solution
The method involves dividing the negative electrode active material layer into central and side parts, applying higher charge current to the central part, and alternating electrochemical charging in separate sections to ensure uniform pre-lithiation, minimizing shaking effects and side reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the negative electrode is allowed to move through roll-to-roll equipment for pre-lithiation, then mass production capability is improved, but shaking occurs in the vertical and horizontal directions causing non-uniform pre-lithiation and lithium precipitation
Solution Approach 1:
The negative electrode active material layer is divided into a central part and side parts. Different charge currents are applied to different regions: a first charge current to the central part and a second charge current (lower than the first) to the side parts. This segmentation allows the process to maintain mass production capability while achieving uniform pre-lithiation by compensating for shaking effects in different regions.
2Productivity
If higher charge current is applied to improve pre-lithiation efficiency, then productivity is improved, but lithium precipitation on bare parts increases
Solution Approach 1:
Different charge currents are applied to different regions of the negative electrode active material layer. The central part receives a higher first charge current for efficient pre-lithiation, while the side parts receive a lower second charge current to prevent lithium precipitation on adjacent bare parts. This local quality approach allows high efficiency while minimizing harmful effects.
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 enhances the quality consistency and lifetime characteristics of the negative electrode by ensuring uniform lithium distribution and preventing lithium precipitation, thereby improving initial efficiency and longevity.
Implementation Method 1
pre-lithiating the negative electrode structure through electrochemical charging while moving the negative electrode structure through the pre-lithiation section
Implementation Method 2
a method of bringing a negative electrode structure and a lithium metal into contact to diffuse lithium into the negative electrode structure
Data Source
AI summary
A method of manufacturing a negative electrode wherein, in the pre-lithiation of a negative electrode structure including a negative electrode active material layer formed therein through electrochemical charging in a roll-to-roll manner, the negative electrode active material layer is divided into a central part and a side part. The charge current applied to the central part is higher than the charge current applied to the side part. In addition, in the method of manufacturing the negative electrode a pre-lithiation section is divided into a first section and a second section, the central part is electrochemically charged in the first section, the side part is electrochemically charged in the second section, and the central part and the side part are alternately electrochemically charged in one or more cycles.