Design of porous metal collector via bubble template-assisted electrochemical deposition using numerical simulation

Abstract

Reduction of resistances in next-generation secondary batteries, which considerably affects battery performance under high-rate conditions, is essential to increase their output density. In particular, lithium-ion batteries (LiBs) require sufficient contact between the collector and the composite electrode layer. However, contact is often disrupted due to the absence of strong bonding. This issue can be redressed using a porous metal to fabricate the collector. In this study, a porous metal structure is theoretically designed and optimized for this purpose. To this end, a numerical model is developed to simulate the formation of the structure via the hydrogen bubble template-assisted electrodeposition method. With the model, the effects of electrodeposition on the process of formation were examined. Via simulation, the performance of the proposed porous metal structure is estimated corresponding to each deposition potential, and the validity of the architecture is confirmed based on experimental results. In addition, a gradient structure is designed to serve as a highly conductive collector during particle packing. The effectiveness of the overall architecture is evaluated via numerical simulation and a multi-step process is proposed to fabricate the gradient structure. Experimental results reveal that the optimal proposed structure exhibits 30% higher conductivity compared to conventional alternatives.

Keywords

• Electrochemical deposition
• Bubble template-assisted method
• Heterogeneous porous structure
• Simulation with electrochemical and mass transport, Effective electrical conductivity