Designing Low Tortuosity Electrodes through Pattern Optimization for Fast-Charging.

Abstract

The development of fast-charging technologies is crucial for expediting the progress and promotion of electric vehicles. In addition to innovative material exploration, 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. To realize the industrialization of low-tortuosity electrodes, a facile, cost-effective, highly controlled, and high-output continuous additive manufacturing roll-to-roll screen printing technology is proposed to render customized vertical channels within electrodes. Extremely precise vertical channels are fabricated by applying the as-developed inks, using LiNi0.6 Mn0.2 Co0.2 O2 as the cathode material. Additionally, the relationship between the electrochemical properties and architecture of the channels, including the pattern, channel diameter, and edge distance between channels, is revealed. The optimized screen-printed electrode exhibited a seven-fold higher charge capacity (72mAhg-1 ) at a current rate of 6C and superior stability compared with that of the conventional bar-coated electrode (10mAhg-1 , 6C) at a mass loading of 10 mgcm-2 . This roll-to-roll additive manufacturing can potentially be applied to various active materials printing to reduce electrode tortuosity and enable fast charging in battery manufacturing.