Today I am taking on Rubén Lijó’s Ciencia Clip Challenge, and I am really excited to
show you this one!
Not only will I be telling you all about how the recently developed glass batteries work,
but you will also get to meet the charming and inspiring senior researcher Helena Braga,
who was instrumental in bringing this technology to fruition - but before we delve into the
sciencey goodness, I want to tell you a bit more about Ciencia Clip Challenge: if you’re
a 13 to 18 year old student who can speak English or Spanish - this science communication
competition is for you, all you need to do is make a 3-5 minute video about any aspect
of science, for a chance to win some very exciting prizes - but for now, let’s go
into the *shattering* news.
[Intro by Caro Waro & Cristina de Manuel]
It was in the late nineteen seventies when John Goodenough developed the first lithium
ion batteries, right here, at the University of Oxford.
Today, forty years later, lithium ion batteries are still the standard in rechargeable batteries
and can be found in most electronic devices.
However, you may have seen the news of some promising ‘glass’ batteries, which represent
a safer and longer-lasting version of the lithium ion battery - and today, with the
help of senior researcher Helena Braga, we are going to explain the significance of this
technological development.
But in order to understand the glass batteries, we need to understand how a standard lithium
ion battery, just like this one, works in the first place.
If you were to open up a lithium ion cell, you would probably find a jelly roll of three
sheets: the anode, the cathode, and between them a separator soaked in liquid electrolyte.
When powering a device and discharging a battery, this set up allows ions and electrons to take
separate routes - the electrons go through an external and separate circuit that powers
a device, whereas the ions cross from anode to cathode going through the liquid electrolyte,
and regroup with their electrons on the other side.
Generally, the anode is made of sheets of graphite with lithium intercalated between
them, whereas the cathode is made out of a lithium metal oxide, often lithium cobalt
oxide.
The lithium ion works reasonably well with the exception of one major vulnerability - when
you have a liquid electrolyte, it is essential to have a physical separator between the anode
and the cathode to prevent short-circuiting.
However, there are instances, particularly during charging, where the liquid electrolytes
favour the build-up of lithium metal deposits on nucleation sites at the base of the electrode,
and there they begin to form sword-like structures known as dendrites.
“Liquid electrolyte creates a nucleus, so it nucleates in 3D and growth of 3D lithium
are like swords can penetrate the separator and produce a short circuit.
cellphones and so on.”
The rate at which dendrites form is unpredictable, but the more you charge and discharge a battery,
the more likely they are to form.
If the dendrites grow long enough, they can pierce the separator and connect the anode
to the cathode, leading to a dangerous short circuit, so obviously you want to build a
battery that doesn’t form dendrites in the first place, and one way of doing this is
by using a solid state electrolyte, which is precisely what these glass batteries are.
“With liquid electrolyte you need a separator, but with the glass you don’t need it”
“Glass enables deposition of lithium to be homogeneous”
“If you have a homogeneous growth of lithium, no dendrites are going to be formed, there
will be no short circuits inside the cell.”
“Glass has a wide electrochemical window, which means that it can work will work with
all pairs of electrode without oxidising, and will not promote internal reactions inside
the cell that can lead to an explosion.”
It should be noted that the glass itself is more of an amorphous solid.
“Glass is applied to a matrix, like very thin paper, recyclable paper.”
This makes it a very flexible sheet that provides robust protection against damage, such as
dropping the battery.
Some of these new solid state electrolyte batteries may also be more environmentally
friendly.
“We are not only working on Lithium, but also on Sodium, totally disposable.
Everything in the sodium cell you can have it in the sea in the water, every single element
that we used you can have it in sea water.”
The main drawback from batteries containing lithium is that the lithium metal and the
materials that form the cathode need to be removed before being disposed, so they aren’t
as easily recyclable.
I also asked Helena how soon it would be before these batteries would be found in our devices!
“Doesn’t depend on us.
We make research and small cells with 9mg of Lithium - they are very small coin cells.
Not the dimension of a cell for a car or a computer, these developments will depend on
the industry.
What we can say is we think it is simple to scale up - the metals aren’t hard to implement
into existing set ups.”
So let’s hope industry decides to scale up on the production of these batteries - it’s
been a while since any major advancements have been made in battery science, and who
knows where Helena’s research will take us next!
“I was interested in materials, started a PhD in the engineering in materials.
When you start going through that pathway, you don’t know where it’s going to take
you.
I love Antonio Machado, “caminante no hay camino, se hace el camino al andar” “
It was an absolute privilege to talk to Helena
about her research!
Our full conversation was around 40 minutes so if you would like to read more about her
research and her trajectory as a scientist, I invite you to check out the full interview
on drawcuriosity.com to find out more!
Thank you so much for sharing your time and knowledge with us :)
Now - back to Ciencia Clip challenge!
If you speak Spanish, you can follow the relevant links to the competition rules in the description.
If you’re English, I have translated the world-wide entries rule for you.
It would be wonderful to see some Draw Curiosity viewers entering!
Personally, I believe that to communicate science effectively you only need two things:
a bit of research - which can be done through reading books and papers, or by interviewing
an expert directly, and a true passion for the subject!
And of course, before I sign out, it’s time for me to challenge the next person in line
- CharlyLabs!
Charly, para el Ciencia Clip Challenge te reto a que nos cuentes cómo las aves han
inspirado la tecnología moderna.
Podréis ver su respuesta la semana que viene en su canal, y todas los ciencia clip challenge
anteriores en esta lista de reproducción!
And as always, thank you so much for watching me, I’ll see you in the next one!
Bye :)
[MUSIC:Thastor & CryoSleepKitten] [ART: Caro Waro & Cristina de Manuel]
[Hosting, scripting, editing: Inés Dawson] [With special thanks to Helena Braga]
[Translated by {your name} into {language}]