Bio-inspired Batteries
仿效生物的電池
By Thomas Lee
李浩賢
A
typical batter y is composed of two
electrodes, an anode and a cathode, which
are immersed in a vial of electrolyte solution.
Commonly used lithium-ion batteries use lithium
ions as the electrolyte, which migrate to the
anode during recharging. Most anodes in lithium-
ion batteries today are composed of graphite,
for its superior electric conductivity. However, the
production cost of graphite anodes has seen a
significant increase recently due to the high cost
of purification, reduced flake graphite production,
and higher tax rates imposed on the commodity.
Graphite’s superior conductivity is a result of
its bonding structure. Its stacks of planar sheets
of delocalised electrons, similar to a metal, allow
free electrons to move and conduct electricity.
With an anticipated surge in the demand of
batteries for electronics, numerous attempts have
been made to develop alternatives to graphite
electrodes but which match the conductivity.
Engineers and scientists are turning to the
diverse and unique microstructures of
feedstock, such as certain pollens
and mushrooms, and
are exploring the
use of carbon
microarchitecture in biomass as material to create
anodes.
Hard carbon structures derived from bee
pollen or bulrush pollen has been found to have
potential for anode applications in energy storage
devices [1]. In a process known as pyrolysis,
pollen is treated with argon gas under high
temperatures to form porous carbon structures.
The research found that the porosity of the unique
microstructures (the samples contained high levels
of oxygen content) maximised the energy storage
capacities, instilling potential anode applications
to this clean and renewable technology.
Engi neer s at UC River side have created
yet another type of lithium-ion battery anode
using the skin of portabella mushrooms caps [2].
Known to be highly porous, the nano-ribbon-like
architectures in the cap skins not only contain
plenty of small apertures for liquid or gas to pass
through, but they also create more chambers for
energy storage and transfer upon heat treatment.
These chambers are essential for improving
battery performance. In a similar process to the
previously mentioned pollen processing, the cap
skin tissue also undergoes pyrolysis to create the
desi red carbon morphologies. As
blind pores in the carbon structure
This article may be useful as supplementary reading for chemistry classes, based on the DSE syllabus.
根據化學科文憑試課程綱要，本文或可作為有用的補充讀物。
