Why Solid-State Batteries Hold the Key to Safer, Denser Energy
Lithium-ion dominates thanks to high energy density and versatility, yet flammable liquid electrolytes limit how far the technology can go. Solid-state batteries promise safer, denser energy storage, but face a critical challenge: voids and lithium dendrites that short-circuit cells. By borrowing insights from soft-adhesive physics, researchers are rethinking interfaces to overcome these failure modes—unlocking a solid-state market poised for rapid growth if the science can keep up.
Transcript
00:00:05 Good evening. Good evening everybody. Uh my name is Kupal Patel. I'm from India. So today I'm going to talk about little bit about batteries. But I will start with the history of battery. So uh in 1800 Walta invented first battery which is based on chemical reaction. So this is uh Waltech pile which is called as Waltech pile. So you can visit the Walta temple in Komao Italy if you are free
00:00:32 this summer and see this cool uh first initial battery. So it is made up of zinc and copper disc and uh uh it is separated by electrolyte which is soaked cardboard paper or clo soaked in brine and uh then uh from then that point onwards we have different cells Daniel cell bird cell polort cell gravity cell pandrop cell uh groove cell and dun cell but uh fast forward to modern day
00:01:08 batteries. So uh uh the discovery of rechargeable lithium ion battery started with 1912 in 1912 by Gilbert and Lewis which was American inventor. Then uh in 1980s John B. good enough at Oxford University invented lithium cobalt oxide as a cathode and uh sudden and and at the same time Rashid Dajami from Moroccan scientist invented
00:01:39 graphite uh anode. These two invention led to the first battery prototype by Yakira Yoshino of Japan to build first prototype of lithium ion battery in 1985. Then uh that point onwards Sony commercialized uh lithium ion batteries batteries in 1991 and in 2019 uh John B. good enough and Rashid Ayakiro Yoshino won the Nobel
00:02:13 Prize for their inventions. So this is discovery of rechargeable lithiumion batteries. But how does battery works? So uh this is simple schemat simple animation of how lithiumion battery works. So there are three four parts to it. Cathode, anode, separator and electrolyte. So uh as you can see when you charge the battery the lithium ion moves from cathode to anode. Uh it is se
00:02:43 it is it is only uh through electrolyte. Uh and when you discharge the battery it moves from anode to cathode. Uh so this is how lithium battery works and we see typical use cases of battery. So it is used in electric vehicles, your mobile phone, portable uh portable devices. It can be used as energy storage devices. So as uh you have seen the earlier talk where uh where we need storage devices
00:03:19 to store lot of energy uh in future because uh we are moving towards electrification of our uh grids. So why why lithiumion batteries are popular? So as you can see from this graph the specific energy density and volutric energy density is very high for lithiumion batteries. So uh you can store the charge within small volume and you can have higher high energy density
00:03:49 for lighter weight application. Uh it is having long lifespan fast charging and it is versatile. However, uh there are few problems. So, you have seen in current uh news news papers or news channel that uh your the the battery batteries are getting fired and uh uh that is unsafe. This is happening because we are using liquid electrolyte which is flammable. So as we want to
00:04:22 move towards safer operation of batteries and more energy dense batteries, we need something else than liquid electrolyte. So can we choose can we use solid electrolyte instead of liquid electrolyte in lithium ion batteries? Yes, we can use. So in 1831 between 1831 and 1834 Michael Faraday started working with solid state ionics and he uh he he uh laid the foundation
00:04:54 for solid state ionics. So we can use solid electrolyte. However, there are problems with solid electrolyte. As you can see from this images uh when when there is no charging discharging cycle the first image shows the Princeton state of anode and solid electrolyte. After several discharge cycle void nucleates at the interface of you know anode and the solid solid
00:05:22 electrolyte and because of void in the corner of the void uh there is large current which is passing through from anode to sodium electrolyte and because of that after several uh plating cycles the dendride grows from anode to cathode and it shortcircuits the battery. Basically, dendrites are made up of lithium itself and because of that it uh it it is not
00:05:55 commercialized uh yet. So we need to solve this problem. So we can take inspiration from uh cavity formation in soft adhesives. So as you can see uh uh the cavity the the soft adhesive layer is sandwiched between steep substrate and uh and the uh steep backing. And when you pull the tape from the substrate cavity nucleates in the adhesive layers and this is the
00:06:27 cavitation problem which is going on in scotch tape. And we can take this example as a starting point to solve the cavitation problem in to to solve the voiding problem in batteries. So uh so what is our hypothesis for voiding problem? So lithium is soft viscoplastic material uh and it is subjected to large electric field at the interface of anode and the solid solid electrolyte. Because
00:06:58 of that pressure builds up and because it is incompressible it cannot have so energetically favorable way of deformationation is cavity nucleation because of that uh cavity nucleate. So we can change the surface energy of the material and solve this problem. Uh so this is our hypothesis for our voiding problem and uh uh to uh to showcase the uh to showcase the commercial side of
00:07:29 this uh solid state battery market. It is it is about to grow by 38.75% compounded annual annual uh growth rate from 2024 to 2023 2032. uh so it is going to be a large market but before that we need to solve these problems of dendrite and voiding. I'm happy to take uh questions on this. Thank you.