Hongjie Dai, Chemistry, Stanford University
The demand for batteries is rapidly increasing as more mobile electronic devices, ranging from cell phones to EVs, enter daily use. By 2016, the battery market is expected to reach about $86 billion. Lithium-ion batteries have taken a leading role, although they are ultimately limited by the comparatively low abundance of lithium, which contributes to the relatively high cost of Li-ion technology. Also, the charge and discharge rates of Li-ion batteries are limited by the insufficient conductivity of the available electrolytes.
Nickel/zinc (Ni/Zn) batteries are a type of alkaline rechargeable battery first proposed in 1901. However, the development of rechargeable Ni/Zn batteries has been slowed by the limited cycle life associated with the dissolution of the zinc electrode into solution during discharge, as well as the lower-than-theoretical capacity of the nickel electrode. Developing electrode materials with high specific capacity (i.e., Watt-hours/kilogram) remains a challenge.
The researcher team will synthesize hybrid materials by creating novel electrodes of nickel hydroxide and zinc oxide grown on graphene nanosheets and carbon nanotubes. The goal is to develop a highly reversible Ni/Zn battery with unprecedented electrochemical performance, including close-to-theoretical energy density, high power density and long cycle life at reasonable cost.