Low-Tortuosity Lithium-Ion Electrodes via Screen-Printed Vertical Channels
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Solution Overview
Problem
Current methods for reducing electrode tortuosity in lithium-ion batteries are costly and have low yield rates, with difficulty in precisely designing and controlling channel creation, which hinders the development of fast-charging capabilities.
Innovation Solution
The use of roll-to-roll screen printing to create electrodes with vertically aligned channels, optimizing channel diameter and edge distance, and employing a specific electrode ink composition to enhance charge transport kinetics and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional methods (magnetic field application, extrusion, directional freeze drying) are used to create channels in electrodes, then channel creation is achieved, but the process becomes costly with low yield rates and poor design control
Solution Approach 1:
The patent changes the manufacturing parameters by using screen printing with specific mesh counts (200-400 mesh), ink viscosities (5-20 Pa·s), and printing speeds (5-50 mm/s) to achieve precise channel dimensions (50-500 μm width) while maintaining ease of manufacture through a simple, low-cost process
Solution Approach 2:
The patent replaces complex mechanical systems (extrusion equipment, magnetic field generators, freeze drying apparatus) with a simple screen printing system that uses a mesh screen and squeegee to create channels through direct ink deposition, significantly reducing manufacturing complexity and cost
2Speed
If channel density is increased to reduce tortuosity, then fast-charging capability is enhanced, but manufacturing complexity and cost increase
Solution Approach 1:
The patent segments the electrode into regions with and without channels, using a screen mesh to create a periodic pattern of channels that balances ion transport speed with manufacturing simplicity. The segmentation allows high channel density where needed while maintaining ease of manufacture through repetitive mesh patterns
Solution Approach 2:
The screen printing process serves multiple functions simultaneously: it deposits the electrode ink, creates the channel pattern through the mesh, controls channel dimensions through mesh selection, and enables scalable production. This multi-functionality achieves fast charging without increasing device complexity
Data Source
AI summary
Reduction in the tortuosity of electrodes is a favored strategy to enhance the fast-charging capability of lithium-ion batteries by optimizing the ion-transfer kinetics. A facile, low-cost, highly controllable, and high-output continual additive manufacturing roll-to-roll screen printing technology is disclosed herein to render customized vertical channels within electrodes. High-accuracy vertical channels were fabricated by applying as-developed inks, using LiNi0.6Mn0.2Co0.2O2, for example, as the cathode material. The optimized screen-printed electrode exhibited a seven-fold higher specific charge capacity (72 mAh/g) at a current rate of 6 C and superior stability compared with that of the conventional bar-coated electrode (10 mAh/g, 6 C) at a mass loading of 10 mg/cm2.