Integrated anode electrode composited Cu-Sn alloy and separator for microscale lithium ion batteries

Abstract

A novel integrated electrode structure was designed and synthesized by direct electrodepositing of Cu-Sn alloy anode materials on the Celgard 2400 separator (Cel-CS electrode). The integrated structure of the Cel-CS electrode not only greatly simplifies the battery fabrication process and increases the energy density of the whole electrode, but also buffers the mechanical stress caused by volume expansion of Cu-Sn alloy active material; thus, effectively preventing active material falling off from the substrate and improving the cycle stability of the electrode. The Cel-CS electrode exhibits excellent cycle performance and superior rate performance. A capacity of 728 mA·h·g -1 can be achieved after 250 cycles at the current density of 100 mA·g -1 . Even cycled at a current density of 5 A·g -1 for 650 cycles, the Cel-CS electrode maintained a specific capacity of 938 mA·h·g -1 , which illustrates the potential application prospects of the Cel-CS electrode in microelectronic devices and systems.