New Battery Technology Developed by
MSE Stores Energy 10 Times the Next
Best One
08.12.2015
Renewable energy has attracted great attention due to
growing energy consumption and environmental concern.
The renewable energy such as solar and wind, is featured
by its intermittent and fluctuating nature, requiring largescale electrical energy storage to mitigate its impact to the
grid. Among the various energy storage technologies,
batteries that reversely convert electrical energy into
chemical energy demonstrate great potential. Redox flow
batteries, unlike the conventional batteries, store energy in
the separate tanks instead of battery interior with enclosed
configuration. So the energy and power of flow batteries
are decoupled. This makes flow batteries easily scalable —
the bigger the tanks, the more energy stored. And flow
batteries are much safer than conventional ones since the
energetic materials are not stored within the battery. In addition, the flow batteries can be
designed in great flexibility and thus the installation and maintenance are much easier compared
with the conventional batteries for large-scale application. However, just like the most
commercialized vanadium redox flow battery, flow batteries currently suffer from high cost and
low energy density.
The redox flow lithium battery (RFLB), developed by A/P Wang Qing group, has recently made
a decisive step towards a high energy density and low cost energy storage, which is on the basis
of a novel concept “redox targeting”. In contrast to conventional flow batteries, the energy of
RFLB is not stored in the electrolyte fluids but in the solid lithium-ion battery materials kept in
the tanks. So the energy density of RFLB is much higher (10 times) than the conventional liquid
redox flow battery. In RFLB, as the energy storage materials are not in the cell, the reactions of
the battery are mediated by the redox mediators dissolved in the electrolyte fluids. The latter
works as redox “shuttles” to carry the charge from the tank to the cell and generate electricity
during discharge process, or the opposite way during charge process.
Besides high energy density, other advantages of RFLB include: (1) Compared with the
commercial lithium ion batteries, no binder and bulky conducting additives are required, which
makes the loading of energy storage materials very easy. (2) RFLB has greater tolerance to the
volume variations of electrodes during repeated lithiation/delithiation cycles — one of the most
challenging technology barriers for achieving long cycle life. (3) RFLB has greater tolerance to
overcharging/ overdischarging and hence safety, since the active materials are not directly
charged or discharged. Additionally, owing to the high energy density, the RFLB has great
promise for electrical vehicle application if the power performance could be further improved,
for which the conventional vanadium flow battery simply cannot be used due to the low energy
density.
The relevant work has been published in
Q. Huang, et al., Phys. Chem. Chem. Phys., 15 (6), 1793-1797 (2013).
F. Pan, et al., Adv. Energy Mater., 4 (15), 1400567 (2014).
C. Jia, et al., Science Advances, 1 (10), e1500886 (2015).
See highlights in ScienceNOW, PhysicsWorld, IEEE Spectrum.