How batteries work - Adam Jacobson

电池是如何工作的 - Adam Jacobson

2,497,752 views ・ 2015-05-21

TED-Ed


请双击下面的英文字幕来播放视频。

翻译人员: Zongzhen Yang 校对人员: Yolanda Zhang
00:06
You probably know the feeling.
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你或许知道那种感觉。
00:08
Your phone utters its final plaintive "bleep"
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你的手机发出最后的,可悲的哔哔声
00:12
and cuts out in the middle of your call.
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然后中断了你的通话。
00:14
In that moment, you may feel more like throwing your battery across the room
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在那个瞬间,比起唱赞歌, 你更想把你的电池怒摔到
00:18
than singing its praises,
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房间的另一边,
00:20
but batteries are a triumph of science.
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不过电池可是科学届的一项巨大成就。
00:24
They allow smartphones and other technologies to exist
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它们使智能手机和 其他科技在我们不需要
00:28
without anchoring us to an infernal tangle of power cables.
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随时携带恶魔般恼人的 电源线的情况下存在。
00:32
Yet even the best batteries will diminish daily,
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即使如此, 连最好的电池也会逐日消耗,
00:35
slowly losing capacity until they finally die.
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慢慢的失去它的容电量直到 最后再也无法供电。
00:39
So why does this happen,
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这为什么会发生呢?
00:41
and how do our batteries even store so much charge in the first place?
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还有我们的电池最初是 如何存放如此多电荷的呢?
00:45
It all started in the 1780s with two Italian scientists,
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这一切都始于18世纪80年代, 有两名意大利科学家
00:50
Luigi Galvani and Alessandro Volta,
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Luigi Galvani和Alessandro Volta,
00:53
and a frog.
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还有一只青蛙。
00:55
Legend has it that as Galvani was studying a frog's leg,
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根据传说,Galvani在研究青蛙腿时,
00:58
he brushed a metal instrument up against one of its nerves,
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用一个金属的装置逆向刷理神经,
01:02
making the leg muscles jerk.
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使青蛙腿发生抖动。
01:04
Galvani called this animal electricity,
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Galvani把这叫做动物电,
01:07
believing that a type of electricity was stored in the very stuff of life.
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他认为这是一种储存在生命体 某个特殊部位的电。
01:12
But Volta disagreed,
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但是Volta不同意,
01:13
arguing that it was the metal itself that made the leg twitch.
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他认为是金属本身导致了腿的颤抖。
01:17
The debate was eventually settled with Volta's groundbreaking experiment.
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这个争论最终以Volta的 一个创新实验宣告结束。
01:22
He tested his idea with a stack of alternating layers of zinc and copper,
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他使用了一摞锌铜交互的金属层,
01:27
separated by paper or cloth soaked in a salt water solution.
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每两层间都由浸泡过盐溶液的纸或布分开, 以此来验证他的想法。
01:32
What happened in Volta's cell is something chemists now call oxidation and reduction.
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Volta的电池中发生的就是化学家们 如今称作氧化和还原的反应。
01:38
The zinc oxidizes, which means it loses electrons,
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锌被氧化了,这意味着它失去了电子,
01:42
which are, in turn, gained by the ions in the water in a process called reduction,
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这些电子被水中的离子 通过还原反应吸走了,
01:48
producing hydrogen gas.
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从而产生了氢气。
01:50
Volta would have been shocked to learn that last bit.
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Volta如果得知最后这一点的话 一定会很震惊。
01:53
He thought the reaction was happening in the copper,
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他以为反应是在铜层发生的,
01:56
rather than the solution.
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而不是在溶液中。
01:58
None the less, we honor Volta's discovery today
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尽管如此,我们如今仍然把电势的
02:01
by naming our standard unit of electric potential "the volt."
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标准单位命名为伏特(Volt), 以此表彰他的贡献。
02:05
This oxidation-reduction cycle creates a flow of electrons between two substances
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这个氧化还原周期创造了 两个物质间的电子流动,
02:11
and if you hook a lightbulb or vacuum cleaner up between the two,
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如果你将一个灯泡或吸尘器放在中间,
02:15
you'll give it power.
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你就会为它供电。
02:17
Since the 1700s, scientists have improved on Volta's design.
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18世纪后, 科学家们改进了Volta的设计。
02:21
They've replaced the chemical solution with dry cells filled with chemical paste,
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他们用充满化学粘浆的 干电池取代了化学溶液,
02:26
but the principle is the same.
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但工作原理是一样的。
02:28
A metal oxidizes, sending electrons to do some work
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一种金属被氧化,释放电子并做功,
02:32
before they are regained by a substance being reduced.
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然后这些电子会进入被还原的物质中。
02:35
But any battery has a finite supply of metal,
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但是任何电池的金属补给都是有限的,
02:38
and once most of it has oxidized, the battery dies.
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一旦金属的大部分被氧化, 电池就无法工作了。
02:42
So rechargeable batteries give us a temporary solution to this problem
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所以充电电池通过可逆转的氧化还原过程
02:46
by making the oxidation-reduction process reversible.
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暂时解决了这个问题。
02:50
Electrons can flow back in the opposite direction
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电子可以通过充电作用
02:53
with the application of electricity.
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从而发生逆向流动。
02:56
Plugging in a charger draws the electricity from a wall outlet
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接通充电器能够引入 墙壁插座中的电流,
02:59
that drives the reaction to regenerate the metal,
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这一反应可以恢复金属的供电能力,
03:02
making more electrons available for oxidation the next time you need them.
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当你下次需要的时候会有 更多电子参与氧化反应。
03:07
But even rechargeable batteries don't last forever.
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但是充电电池也不可能永久持续供电。
03:10
Over time, the repetition of this process causes imperfections
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随着使用时间增加, 过程的反复会导致金属表面发生
03:14
and irregularities in the metal's surface that prevent it from oxidizing properly.
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消耗和不规则缺损, 无法进行正常的氧化反应。
03:19
The electrons are no longer available to flow through a circuit
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电子再也无法形成电流通路,
03:22
and the battery dies.
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电池也就失去了供电功能。
03:24
Some everyday rechargeable batteries
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有些日常的充电电池
03:27
will die after only hundreds of discharge-recharge cycles,
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只经过几百个充电周期就会坏掉,
03:31
while newer, advanced batteries can survive and function for thousands.
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但是高级一些的电池可以存活并 正常工作长达几千个周期。
03:36
Batteries of the future may be light, thin sheets
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未来的电池可能会变成很轻的薄片,
03:39
that operate on the principles of quantum physics
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依据量子物理的原理工作,
03:42
and last for hundreds of thousands of charge cycles.
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可以完成几十万次的充电周期。
03:45
But until scientists find a way to take advantage of motion
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但是直到科学们找到 通过运动充电的方法,
03:49
to recharge your cell battery, like cars do,
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像汽车的充电电池那样,
03:51
or fit solar panels somewhere on your device,
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或者将太阳能板安装到 你的移动设备上,
03:54
plugging your charger into the wall,
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将充电器插入墙壁,
03:56
rather than expending one battery to charge another
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而非消耗一个电池 去为另一个装置充电,
03:59
is your best bet to forestall that fatal "bleep."
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才是最好的预防致命的哔哔声的方法。
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