Enhancing the Capacity and Cycling Performance of Lithium Ion Batteries Through Perforated Current Collectors

Abstract

Lithium ion batteries are important for new energy technologies and manufacturing systems. However, enhancing their capacity and cycling stability poses a significant challenge. This study proposes a novel method, i.e., modifying current collectors with perforations, to address these issues. Lithium ion batteries with mechanically perforated current collectors are prepared and tested with charge/discharge cycles, revealing superior capacity as well as enhanced electrochemical stability over cycles. Impedance spectroscopy, scanning electron microscopy, and peeling tests are conducted to investigate the underlying mechanisms. Higher peel resistance, minimized interface cracking, and reduced electrical impedance are found in the perforated electrodes after cycles. Investigations indicate that the perforation holes on current collectors allow the active materials coating on the two sides of the current collector to bind together and, thus, lead to enhanced adhesion between the current collector and active layer. Mechanical simulation illustrates the role of perforated current collectors in curbing interface cracking during lithiation, while electrochemical simulation shows that the interfacial cracking hinders the diffusion of lithium ions, thereby increasing battery impedance and reducing the cyclic performance. This investigation reveals the potential of designing non-active battery components to enhance battery performance, advocating a nuanced approach to battery design emphasizing structural integrity and interface optimization.