How Batteries Work: Energy Storage Chemistry
This podcast explains how batteries function as electrochemical devices that store and release electrical energy. They convert chemical energy into electrical energy through redox reactions. Key components include two electrodes, the anode (negative) and cathode (positive), separated by an electrolyte.
During charging, electrons move from the cathode to the anode, increasing chemical potential energy, while ions move through the electrolyte to balance the charge. When discharging, this stored chemical potential energy is converted back to electricity as electrons flow in the opposite direction through an external circuit, powering a device.
The overview highlights that rechargeable batteries allow this chemical reaction to be reversible, enabling repeated charge-discharge cycles. Factors like battery chemistry, capacity (measured in Ah or Wh), voltage, temperature, state of charge (SOC), charging/discharging rates, and cycle life affect performance and lifespan. Common types discussed include lead-acid and lithium-ion batteries, with the latter noted for its high energy density, long life, and efficiency.
Battery energy storage is crucial for integrating renewable energy sources (like solar and wind) into the electricity supply by storing excess energy for later use, stabilizing the grid, and reducing fossil fuel dependency, especially for electric vehicles. Research, particularly by the DOE Office of Science, focuses on improving materials for anodes, cathodes, and electrolytes to develop highly efficient and safe next-generation electrical energy storage solutions.
0.000000 1.800000 - Welcome to Everyday Explained.
1.800000 4.360000 Your daily 20-minute dive into the fascinating house
4.360000 6.360000 and wise of the world around you.
6.360000 8.240000 I'm your host, Chris, and I'm excited
8.240000 9.920000 to help you discover something new.
9.920000 11.200000 Let's get started.
11.200000 13.000000 - You know that feeling, right?
13.000000 14.800000 Your phone battery just dies,
14.800000 16.200000 like right when you need it most.
16.200000 18.200000 - Oh yeah, the perfect photo op gone.
18.200000 21.760000 - Exactly, or the TV remote gives up the ghost
21.760000 24.040000 just before the season finale reveal.
24.040000 24.880000 - I'm sold the time.
24.880000 27.600000 - We realize so much on these little power packs
27.600000 31.320000 every single day, but have you ever stopped to think
31.320000 35.000000 how they actually store and then release all that energy?
35.000000 37.480000 - It's not just magic, even though it feels like it sometime.
37.480000 39.560000 - Right, it feels like this tiny trick,
39.560000 41.520000 but it's actually some pretty complex chemistry
41.520000 45.120000 happening under the hood in your pocket.
45.120000 47.080000 So today we're doing a deep dive.
47.080000 52.080000 We're jumping into the honestly fascinating world of batteries.
52.080000 54.720000 We're gonna unpack how they work,
54.720000 57.800000 what makes some last longer, maybe why your phone battery
57.800000 60.400000 isn't what it used to be, and we'll even peek into the future.
60.400000 61.440000 - It's a big topic.
61.440000 63.440000 - Think of it as your like essential guide
63.440000 65.680000 to understanding these devices that power
65.680000 67.200000 basically everything now.
67.200000 70.280000 - And what's really cool I think is how this simple act
70.280000 72.240000 getting power from a battery,
72.240000 75.280000 it rests on these really intricate chemical reactions.
75.280000 76.120000 - Yeah.
76.120000 78.040000 - It's all about converting stored chemical energy
78.040000 80.080000 into electricity, right when you need it.
80.080000 82.280000 It's kind of an elegant dance of tiny particles.
82.280000 84.280000 - An elegant dance, I like that.
84.280000 85.960000 We'll try and break down that dance for you today.
85.960000 88.120000 - Okay, let's get into it then.
88.120000 91.720000 Prepare to understand the hidden superpowers
91.720000 93.320000 inside every battery.
93.320000 95.760000 So let's start big picture.
95.760000 98.000000 What is a battery, fundamentally?
98.000000 100.720000 It's gotta be more than just a container for electricity.
100.720000 103.800000 - Exactly, it's not just holding ready made electricity.
103.800000 107.320000 Batteries are devices that accept energy, store it,
107.320000 109.920000 and then release it as electricity when you need it.
109.920000 110.760000 - Okay.
110.760000 113.080000 - But the key thing, the real trick is that they store
113.080000 115.200000 electricity energy using chemistry
115.200000 116.760000 in the form of chemical potential.
116.760000 119.520000 - Chemical potential, like a firewood.
119.520000 122.480000 - Sort of, think about wood burning the chemical energy
122.480000 125.520000 in the wood and oxygen turns into heat and light,
125.520000 127.840000 or gasoline in an engine becoming motion.
127.840000 128.680000 - Right.
128.680000 130.800000 - For batteries electricity is first converted
130.800000 132.840000 into this chemical potential form,
132.840000 135.960000 like winding up a spring, so it could be stored efficiently.
135.960000 138.120000 - Okay, so it's like a chemical energy vault,
138.120000 139.760000 a tightly wound spring.
139.760000 143.920000 But how does it know when to, you know, unwind,
143.920000 145.680000 when to let the electrons out?
145.680000 147.440000 - Good question.
147.440000 149.840000 That gets us to what's inside this vault.
149.840000 154.240000 Every battery basically has two key parts,
154.240000 156.760000 electrical terminals called the cathode and the anode.
156.760000 158.160000 - Cathode and anode, okay.
158.160000 159.840000 - And they're separated by this chemical stuff
159.840000 160.760000 called an electrolyte.
160.760000 163.360000 - Electrolyte, like in sports drinks.
163.360000 166.160000 - Well, chemically similar in that it involves ions,
166.160000 169.040000 but here it's a crucial internal pathway.
169.040000 170.680000 So when you connect the battery
170.680000 172.160000 to something your phone, a flashlight,
172.160000 174.160000 whatever you complete the external circuit.
174.160000 175.680000 - And that's when the show begins inside.
175.680000 177.000000 - That's when the dance starts, yeah.
177.000000 178.960000 - All right, this is where it gets really cool, I think.
178.960000 181.400000 The electron ballet, you called it.
181.400000 185.640000 How do these parts anode, cathode, electrolyte work together?
185.640000 187.280000 - It's very precise choreography.
187.280000 191.000000 When the battery is discharging, powering your device,
191.000000 193.600000 electrons flow from the anode through your device.
193.600000 194.440000 - Giving a power.
194.440000 195.280000 - Exactly.
195.280000 196.760000 And then they travel to the cathode.
196.760000 198.480000 That's the external circuit.
198.480000 200.520000 - But simultaneously inside the battery,
200.520000 203.640000 dot ions, which are charged atoms or molecules,
203.640000 205.280000 are moving through that electrolyte.
205.280000 207.800000 - Okay, so stuff is moving outside and inside.
207.800000 210.640000 - Critically, these ions moving inside
210.640000 212.720000 through the electrolyte are essential.
212.720000 214.880000 They basically balance the charge.
214.880000 217.320000 Without them, the flow of electrons outside
217.320000 219.160000 would just stop almost immediately.
219.160000 221.600000 - Ah, so they complete the circuit internally?
221.600000 222.760000 - Precisely.
222.760000 224.720000 And the direction is key.
224.720000 227.400000 When you're charging a rechargeable battery,
227.400000 229.800000 you're using external power to push electrons
229.800000 231.520000 from the cathode to the anode.
231.520000 232.800000 - Okay, reversing the flow.
232.800000 233.640000 - Yep.
233.640000 236.280000 And this increases the stored chemical potential energy.
236.280000 238.000000 You're winding that spring back up.
238.000000 238.920000 - Filling the vault.
238.920000 239.760000 - Right.
239.760000 241.840000 Then when you're discharging, using the battery,
241.840000 243.440000 it's the natural flow.
243.440000 244.680000 Electrons go the other way.
244.680000 247.640000 From anode to cathode through your device.
247.640000 250.520000 - Converting that chemical energy back into electricity.
250.520000 251.520000 - Exactly.
251.520000 254.640000 And the ions move accordingly inside to keep it all balanced.
254.640000 257.760000 That balances what makes it rechargeable and sustainable.
257.760000 259.400000 - So it's not just the electrons we use.
259.400000 262.440000 The ions are like the unsung heroes inside,
262.440000 263.480000 balancing the books.
263.480000 264.920000 That's actually pretty neat.
264.920000 266.720000 Especially considering this basic idea
266.720000 269.360000 goes back to Volta in what, 1800?
269.360000 272.400000 - Yeah, the fundamental principle is surprisingly old.
272.400000 275.920000 But refining it is where all the modern magic happens.
275.920000 277.000000 - Which brings up a good point.
277.000000 280.440000 We all know some batteries just seem better.
280.440000 283.280000 Or maybe more frustratingly, they degrade.
283.280000 286.800000 - My phone battery definitely doesn't last like it used to.
286.800000 287.640000 Why is that?
287.640000 289.000000 What's happening chemically?
289.000000 289.920000 - That's a great question.
289.920000 292.040000 And honestly, it's something scientists
292.040000 293.520000 are still digging deep into.
293.520000 294.360000 - Right.
294.360000 295.800000 - Even though batteries are old tech and principle.
295.800000 296.640000 - Right.
296.640000 298.680000 - Those chemical reactions inside,
298.680000 301.400000 they aren't perfectly 100% reversible
301.400000 303.360000 every single time you charge and discharge.
303.360000 304.200000 - Ah, okay.
304.200000 306.400000 So it's not a perfect reset each cycle.
306.400000 307.240000 - Not quite.
307.240000 309.120000 Tiny side reactions happen.
309.120000 311.360000 Materials can change structure slightly over time.
311.360000 314.440000 They give it like photocopying a photocopy repeatedly.
314.440000 316.080000 - Yeah, it gets fuzzier each time.
316.080000 316.920000 - Exactly.
316.920000 319.840000 These small cumulative changes eventually add up.
319.840000 321.800000 They reduce the battery's capacity,
321.800000 324.800000 how much energy it can hold its overall performance,
324.800000 326.680000 and sometimes even its safety.
326.680000 328.280000 - So what are the main things that affect
328.280000 331.640000 how well a battery performs and how long it lasts?
331.640000 333.360000 Besides just using it a lot.
333.360000 335.000000 - Well, several factors play a big role.
335.000000 336.640000 Performance and capacity,
336.640000 339.280000 which we usually measure in ampere hours,
339.280000 340.120000 or watt hours.
340.120000 341.840000 - Right, you see those numbers on battery packs?
341.840000 343.800000 - Yep, they tell you how much energy it stores.
343.800000 348.240000 So key factors include the specific battery chemistry itself
348.240000 350.800000 with the anode cathode and electrolyte are made of.
350.800000 351.640000 That's huge.
351.640000 352.480000 - Excellent.
352.480000 354.960000 - Then there's its voltage, the electrical pressure,
354.960000 357.040000 so to speak, and temperature is a big one.
357.040000 358.800000 Extreme heat or cold.
358.800000 361.000000 Really bad for efficiency and lifespan.
361.000000 363.960000 - Okay, avoid leaving my phone in the car on a hot day.
363.960000 365.480000 - Definitely good advice.
365.480000 367.880000 Also, how you use it matters.
367.880000 371.440000 Like the state of charge, SOC, how full you keep it,
371.440000 374.160000 and the depth of discharge, DOD,
374.160000 375.920000 how much you drain at each time.
375.920000 378.960000 - So running it totally flat all the time might not be great.
378.960000 380.320000 - For some chemistry, is yeah.
380.320000 382.560000 And then there's the infamous memory effect.
382.560000 384.520000 - Yeah, I've heard of that, is that real?
384.520000 387.000000 - It was very real, especially for older chemistries,
387.000000 388.480000 like nickel cadmium.
388.480000 392.120000 If you repeatedly charge them without fully discharging first,
392.120000 394.640000 they could sort of learn that lower capacity limit.
394.640000 395.960000 - Like the battery gets for deathful
395.960000 397.680000 about how full it can actually get?
397.680000 398.520000 - Kind of, yeah.
398.520000 401.120000 It's a real chemical phenomenon in certain types.
401.120000 403.720000 Less of an issue for modern lithium ion, thankfully.
403.720000 405.080000 - Okay, so it sounds like the chemistry
405.080000 406.720000 is a really big deciding factor.
406.720000 409.720000 Are there main families of batteries we should know about?
409.720000 410.880000 - Absolutely.
410.880000 413.240000 The choice of materials for electrodes and electrolytes
413.240000 414.880000 makes all the difference.
414.880000 417.760000 Today, the two big players you'll encounter most
417.760000 420.800000 are lead acid and lithium ion.
420.800000 421.800000 - Lead acid?
421.800000 422.760000 I don't know if that's familiar.
422.760000 423.560000 Cars, right?
423.560000 424.320000 - Exactly.
424.320000 427.520000 They're the venerable grandparents of rechargeable batteries.
427.520000 429.520000 They've been around for over 170 years.
429.520000 430.360000 - Wow.
430.360000 432.520000 - They're pretty economical, very reliable
432.520000 436.520000 for things like starting cars or providing backup power.
436.520000 438.560000 They use lead electrodes, obviously.
438.560000 440.440000 And sulfuric acid is the electrolyte.
440.440000 441.280000 - Simple enough.
441.280000 443.600000 - Yeah, when they discharge, the acid basically
443.600000 446.560000 turns into water as part of the reaction,
446.560000 448.080000 charging reverses it.
448.080000 450.800000 But they are heavy, bulky for the power they give.
450.800000 452.440000 - Lower energy density, I guess.
452.440000 453.280000 - Right.
453.280000 456.440000 And they need some maintenance plus there's toxic lead involved.
456.440000 458.680000 - Okay, the old workhorse, what about the other one?
458.680000 459.920000 Lithium ion.
459.920000 462.000000 - Ah, lithium ion.
462.000000 463.600000 These are the modern superstars.
463.600000 466.080000 So important, their development won the Nobel Prize
466.080000 468.240000 in chemistry back in 2019.
468.240000 469.080000 - Really?
469.080000 470.320000 What makes them so special?
470.320000 472.400000 - They work by shuttling lithium ions,
472.400000 474.600000 hence the name back and forth between the cathode
474.600000 476.720000 and anode through the electrolyte.
476.720000 479.160000 They're big advantages, high energy density.
479.160000 481.720000 - So more power, less weight in space,
481.720000 483.280000 like in phones and laptops.
483.280000 484.240000 - Exactly.
484.240000 485.600000 They also tend to have a long life.
485.600000 487.280000 They handle temperature swings better,
487.280000 489.560000 charge up pretty quickly, and crucially,
489.560000 491.520000 they don't really suffer from that memory effect
491.520000 492.360000 we talked about.
492.360000 493.360000 - That's a big plus.
493.360000 495.880000 - Huge plus, and just for comparison,
495.880000 498.800000 a good lithium ion battery might handle say,
498.800000 501.760000 up to 2500 charge, this charge cycles.
501.760000 504.160000 That acid is more like 1500 typically.
504.160000 506.720000 - Okay, yeah, that's a significant difference.
506.720000 510.760000 From the steady old workhorse to this high performance
510.760000 512.600000 athlete of the battery world,
512.600000 515.040000 amazing how far the science has pushed things.
515.040000 516.040000 - It really is.
516.040000 518.600000 And if we zoom out a bit, think bigger picture.
518.600000 522.440000 Batteries aren't just for our gadgets anymore.
522.440000 524.280000 They're becoming absolutely essential
524.280000 525.800000 for our energy grid.
525.800000 528.320000 - How so, you mean for electric cars?
528.320000 530.440000 - Well, yes, that's part of it, the big part.
530.440000 532.920000 But also for integrating renewable energy
532.920000 534.640000 like solar and wind power.
534.640000 536.560000 - Ah, because the sun doesn't always shine
536.560000 537.880000 and the wind doesn't always blow.
537.880000 540.280000 - Exactly, those sources are intermittent.
540.280000 542.520000 So you need a way to store the excess energy
542.520000 544.200000 they generate when they're active.
544.200000 547.200000 And release it later when they're not using giant batteries.
547.200000 550.080000 - Precisely, large scale battery storage systems
550.080000 552.480000 are key to making the grid stable and reliable
552.480000 554.160000 as we add more renewables.
554.160000 555.840000 And actually, there's a really interesting shift
555.840000 557.120000 happening right now.
557.120000 560.920000 In the US, there are now more battery storage projects planned
560.920000 564.120000 or being built than new natural gas power plants.
564.120000 567.000000 - Wow, really, more batteries than gas plants.
567.000000 570.560000 - Yep, it's a major indicator of the energy transition.
570.560000 573.320000 These batteries help stabilize electricity prices,
573.320000 575.560000 make the grid more resilient and, of course,
575.560000 577.440000 reduce our reliance on fossil fuels.
577.440000 578.280000 - That is huge.
578.280000 580.800000 So it's not just about our phones or even our cars,
580.800000 584.400000 it's literally reshaping our national power infrastructure.
584.400000 586.000000 So what's next?
586.000000 590.320000 What are scientists working on to push battery tech even further?
590.320000 591.840000 - Oh, there's a ton of research.
591.840000 594.280000 The scientific community, including groups funded
594.280000 596.560000 by the Department of Energy's Office of Science,
596.560000 600.240000 is working flat out on next-gen energy storage.
600.240000 601.280000 - Like what kind of things?
601.280000 602.840000 - Developing totally new materials
602.840000 605.920000 or improving existing ones for anodes, cathodes,
605.920000 608.440000 electrolytes, they're using supercomputers now
608.440000 610.600000 to model and design new materials,
610.600000 611.560000 atom by atom.
611.560000 613.160000 - Designing batteries on a computer.
613.160000 615.200000 - Yeah, things like the electrolyte genome project
615.200000 618.800000 at JCESR Joint Center for Energy Storage Research.
618.800000 620.600000 They have this massive database,
620.600000 622.720000 like 26,000 different molecules.
622.720000 623.560000 - Wow.
623.560000 625.080000 - And they can computationally screen them
625.080000 627.720000 to predict which ones might make better electrolytes.
627.720000 629.200000 It massively speeds up discovery.
629.200000 630.040000 - That's incredible.
630.040000 630.880000 So the goal is,
630.880000 633.400000 save for batteries, ones that last even longer,
633.400000 636.480000 charge way faster and hold much more energy.
636.480000 638.000000 Think solid state batteries,
638.000000 639.560000 maybe lithium air batteries eventually.
639.560000 641.160000 - Are there still big challenges?
641.160000 642.200000 - Oh, sure.
642.200000 644.280000 Things like thermal runaway and lithium ion
644.280000 646.600000 that rare but dangerous overheating issue
646.600000 649.480000 still needs careful management and better solutions.
649.480000 652.160000 And environmental concerns about sourcing materials
652.160000 653.720000 and recycling are always there.
653.720000 654.560000 - Right.
654.560000 657.440000 - But the potential for innovation is just immense.
657.440000 659.440000 - What a fascinating journey we've taken
659.440000 662.400000 from just chemical potential like wood
662.400000 666.160000 to this incredibly complex dance of electrons
666.160000 668.160000 and ions inside these devices.
668.160000 670.080000 Batteries really are unsung heroes.
670.080000 671.080000 - They absolutely are.
671.080000 672.400000 We've seen how they work,
672.400000 673.560000 what the key parts are,
673.560000 674.800000 why different chemistries matter.
674.800000 676.040000 - And how they're doing so much more
676.040000 677.880000 than just powering our phones now.
677.880000 680.600000 Stabilizing the grid, enabling renewables.
680.600000 681.440000 - Yeah.
681.440000 682.280000 - It's transformative.
682.280000 683.880000 - The impact really is far reaching.
683.880000 686.800000 It's fundamental to a more sustainable energy future.
686.800000 688.520000 - So next time you plug something in
688.520000 690.720000 or maybe start your easy, just take a second.
690.720000 695.240000 Remember that tiny, intricate chemical dance happening inside?
695.240000 696.400000 It's kind of cool reminder
696.400000 699.880000 that even everyday objects rely on some really deep science.
699.880000 700.840000 - Well said.
700.840000 703.360000 - And maybe here's a final thought to leave you with.
703.360000 704.880000 With all this intense research,
704.880000 707.200000 this push for better batteries.
707.200000 710.600000 How different might our world look in, say, 10 or 20 years
710.600000 712.600000 as we get even better at storing energy?
712.600000 714.560000 What possibilities might that unlock?
714.560000 716.760000 It's definitely a charged question to think about.
716.760000 719.840000 - And that wraps up today's episode of Everyday Explained.
719.840000 723.280000 We love making sense of the world around you five days a week.
723.280000 726.160000 If you enjoyed today's deep dive, consider subscribing
726.160000 728.240000 so you don't miss out on our next discovery.
728.240000 730.720000 I'm Chris and I'll catch you in the next one.