Facile synthesis of chain-like LiCoO2 nanowire arrays as three-dimensional cathode for microbatteries

Abstract

Three-dimensional microbatteries have emerged as a new direction for powering microelectronic devices, where the three-dimensional nanostructured electrode is the key component for microbatteries to achieve high power density and high energy density in a small footprint. In this work, we present a novel approach for fabrication of LiCoO2 nanowire arrays as three-dimensional cathode for microbatteries. Mesoporous low-temperature LiCoO2 nanowire arrays can be directly prepared by a two-step hydrothermal method and they can be easily converted into chain-like high-temperature LiCoO2 nanowire arrays through further calcination. The layered LiCoO2 nanowire arrays exhibit both high gravimetric capacity and areal capacity, while maintaining good cycling stability and rate capability. The facile synthesis and superior electrochemical performance of the three-dimensional LiCoO2 cathode make it promising for application in microbatteries. Hui Xia from Nanjing University of Science and Technology in China and colleagues report a three-dimensional (3D) nanowire battery cathode that packs high power and energy into a tiny framework. The team turned lithium cobalt oxide - a compound widely used for lithium-ion battery cathodes - into freestanding, 3D nanowire arrays on metal substrates using a simple two-step hydrothermal synthesis technique. Further heat treatment transformed the nanowires into chain-like structures with first-rate electrochemical and recharging properties thanks to the material's short ion transport lengths and large surface area for energy storage. The cathode helps solve problems associated with delivering sufficient power and high storage capacities for on-chip battery applications - a finding that can aid in the design of advanced microscale devices such as drug delivery systems and wireless sensors. Mesoporous low-temperature LiCoO2 nanowire arrays can be directly prepared by a two-step hydrothermal method and they can be easily converted into chain-like high-temperature LiCoO2 nanowire arrays through further calcination. The layered LiCoO2 nanowire arrays exhibit both high gravimetric capacity and areal capacity, while maintaining good cycling stability and rate capability, make them promising for application in microbatteries.