Nano tin encapsulated in copper grooves as an anode for high-performance lithium-ion batteries

Abstract

With the ever-growing demand for high energy and power density lithium-ion batteries (LIBs), tin (Sn) has been considered a capable anode material because of its high theoretical capacity (993.4 mAh/g). However, the practical application of Sn anodes suffers from low capacity retention due to significant volume expansion (~257 %) and poor ion and electron transportation during cycling. To overcome these problems, a novel architecture is necessary to mitigate volume expansion during cycling without instigating severe electrode fragmentation. In this work, we developed grooves on a copper plate (25 µm thickness) by etching it with SiC sandpaper of different grain sizes (23 µm (#400), 68 µm (#220), and 190 µm (#80)). The Sn (60–70 nm) was inserted in the developed grooves of the copper plate (Sn/Cu) and coated with polyvinylidene fluoride (PVDF) to form a confined structure. The PVDF-coated Sn/Cu plates (#400, #220, and #80) were used as anode materials for LIBs. The prepared electrodes delivered high capacities of 274, 153.7, and 103 mAh/g after 500 cycles at a 0.2 C-rate. The present work opens a novel path for fabricating high-performance LIBs using a simple experimental process.