A good kind of disorder: Boffins boost capacitor tech by disturbing dipoles
- Reference: 1738234992
- News link: https://www.theregister.co.uk/2025/01/30/engineered_materials_to_boost_capacitor/
- Source link:
Different approaches to storing energy in electric circuits have their trade-offs: lithium-ion batteries can store a lot of energy but deliver it slowly, while capacitors can deliver energy quickly but can't store a lot of it, roughly speaking.
To try to square this circle a [1]team of materials science boffins at China's Hefei Institutes of Physical Science, Tsinghua Uni, and Shenyang National Laboratory for Materials Science, developed a composite material which achieved three times the energy density of comparable ceramic capacitors.
[2]
Multilayer ceramic capacitors (MLCCs) — used for many electronic applications, such as smartphones, displays and electric vehicles — consist of vertical stacks of capacitors connected in parallel. The world's largest maker of MLCCs is Murata Manufacturing, based in Japan, which supplies Apple, HP, and Intel.
[3]
[4]
The team made changes to a material group called antiferroelectrics – used in capacitors – in which layers of pairs of positive and negative charges are aligned in one direction alternate with layers in which such dipoles align in the opposite direction. The researchers prepared materials which deliberately disrupt this pattern by including areas of dielectrics – materials with high resistance used in capacitors – which do not exhibit this kind of dipole behavior.
"Overall, capacitors made using this composite material had a greater charge–discharge efficiency and breakdown strength than did devices made using unengineered lead zirconate [a material commonly used in capacitors]," said Piush Behera and Suraj Cheema of MIT in an accompanying [5]article .
[6]
The result was an increase in the number of charge–discharge cycles that occur before breakdown. The maximum energy density was also enhanced compared to unengineered lead zirconate.
[7]BT unplugs plans to turn old cabinets into EV chargepoints
[8]Samsung shows off battery tech it says will see you gone in nine minutes
[9]You look like a fungi. Got mushroom in your life to build stuff with mycelium computers?
[10]China's top EV battery maker announced a breakthrough, but top boffin isn't convinced
While another alternative for high-performance capacitors exists involving thin-film layers, they are not suitable to such a wide range of applications as MLCCs.
Behera and Cheema suggest the combination of "MLCC-like structures that integrate thin-film layers" could result in high energy density, while these "MLCC-like devices" that incorporate the boffins' engineered material "could be promising."
With more development, the technique could also benefit on-chip capacitors, the authors suggest.
"As on-chip capacitor applications continue to advance, frustration-modulated high-performance antiferroelectrics materials can potentially be promising candidates for multilayer, large-scale and three-dimensional capacitors," the study said. ®
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[1] https://www.nature.com/articles/s41586-024-08505-7
[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2Z5uwNNFJjItPH3TcefCxsQAAANY&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44Z5uwNNFJjItPH3TcefCxsQAAANY&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33Z5uwNNFJjItPH3TcefCxsQAAANY&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[5] https://www.nature.com/articles/d41586-025-00085-4
[6] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44Z5uwNNFJjItPH3TcefCxsQAAANY&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[7] https://www.theregister.com/2025/01/20/bt_ev_chargepoints/
[8] https://www.theregister.com/2024/04/25/samsung_battery_twenty_years/
[9] https://www.theregister.com/2019/09/17/like_computers_love_fungus/
[10] https://www.theregister.com/2023/08/24/catl_battery_claim_questioned/
[11] https://whitepapers.theregister.com/
Breakdown?
This statement "the number of charge–discharge cycles that occur before breakdown" got me thinking. Are manufacturers building circuit boards with components that they know are going to fail?
Whats the limit for charge–discharge cycles before breakdown occures and is the breakdown catastrophic?
Re: Breakdown?
Of course they are! But the question should not be "will the magic smoke escape" but "how long before we expect the magic smoke to escape"
Re: Breakdown?
Of course! How else can you ensure the product breaks exactly a week after the guarantee runs out?
Re: Breakdown?
The rep of a clothes dryer once was very angry with me and insisted that I must have done something to it to make it fail under warranty. He insisted they are designed to fail 6 months after, not before. Asked him how long the new motor will last - Oh, the new one will last forever!
Re: Breakdown?
Anyone with a Sinclair ZX spectrum in the attic either knows this already, or will find out when they next try powering it up…
Re: Breakdown?
Everything fails eventually, especially capacitors, and especially bulk storage capacitors i.e. where there is a space/cost constraint against the energy they need to store
Ceramic and Tantalum caps can suffer dendritic growth, which kills them over time if they are used close to their max voltage rating. To make caps last longer, you can overspecify their voltage rating but that adds cost and size. Temperature is also a factor, and the manufacturer will have a reliability curve and a special more expensive series for extended temperature range.
Any caps connected to the mains e.g. on the hot end of power supplies will experience transients that could exceed their rating too.
Is it catastrophic? For tant/mlcc usually yes. They can fail short and explode violently. Electrolytics are usually a bit more forgiving and tend to fail open
HV MLCCs (multilayer ceramic caps) are especially prone to failure near their voltage rating, because they are strings of capacitors in series. The smallest mistolerance in manufacturing, or cycle aging, can mean that one cap in the stack gets a higher voltage than the others, it then fails short, the others then see a proportionally higher voltage, and then you can get a cascade effect
Re: Breakdown?
...and why people restoring old HiFi gear (especially) will often start their task by 're-capping' the beast. It's not an upgrade: it's simply to replace the components that degrade the most with age. I have a tube (valve) radio amp that's been sitting idle for years that I keep meaning to bring back to life...that monster has a cap isolating the 1.2KV anode from the antenna feed so even a partial failure there could prove very interesting indeed!
Re: Breakdown?
One thing I forgot to mention is ripple current i.e. the average charge and discharge current, which depends on the frequency, capacitance and depth of discharge. You can use a cap within its voltage rating but if you charge and discharge at too high a frequency then it will age faster, higher still and it will overheat and fail. Again all this will be on the datasheet from any reputable manufacturer
Re: Breakdown?
Ceramic caps also have thermal stress induced failures. Being ceramic, they're brittle so can fracture when heated and cooled - or put under any mechanical stress really. This isn't great for a component that has to be soldered to a PCB.
Transportation
I was impressed by supercapacitors driving trams in Spain - No overhead wires!
https://www.youtube.com/watch?v=VMRWnYYhi2Y
Re: Transportation
No overhead wires at all? Or just between gantry sections?
Re: Transportation
They charge the SuperCaps at each tram stop using an overhead rail and a raisable commutator, then use the stored energy to get to the next stop. Clever system but I imagine the SuperCaps lifetime is going to be short given how they are used. Personally I would design the commutator to stay up and design the overhead rail at each tram stop with a taper to pickup the commutator. Raising and lowering it constantly is going to wear out the mechanism rapido!
Applications?
As far as I understand, these improved capacitors will not replace Li-Ion batteries, so what kind of improvements can we expect in our phones from this capacity (no pun intended) to discharge more 'quick' energy?
Re: Applications?
Aside from being able to make smaller caps, one advantage I can see is better decoupling: the faster you can 'sink' a spike or unwanted waveform, the better.
Re: Applications?
Smaller, more powerful SMPS enabling things like higher voltage on USB-C to charge phones quicker, would be one.
Speaking of caps...
Slightly off-topic - but as junior techs in a long-gone circuit fabrication shop, our party trick was to wedge a big smoothing electrolytic cap between two filing cabinets and reverse-connect it to a beefy bench PSU. When the remote start was flipped, the resulting 'bang' occasionally threw enough material up to discolour the ceiling tiles. Made the office stink something awful, too, but it didn't half make us giggle when one gave up the ghost in spectacular style!
frustration-modulated
A good description for all of us these days