How batteries work - Adam Jacobson

電池的運作原理 - 亞當．賈寇柏森

譯者: Sophie Lai 審譯者: Harry Chen

You probably know the feeling.

你可能知道這種感覺 －

Your phone utters its final plaintive "bleep"

你的手機發出它最後、悽涼的「嗶」聲

and cuts out in the middle of your call.

然後在你的電話講到一半就斷線了

In that moment, you may feel more like throwing your battery across the room

這時候你可能想把你的電池 扔到房間的另一頭過去

than singing its praises,

而不是大讚其美言

but batteries are a triumph of science.

但是電池是科學的大勝利

They allow smartphones and other technologies to exist

它們讓智慧型手機跟其他科技產品

without anchoring us to an infernal tangle of power cables.

不需把我們和惱人、 糾結不清的電源線綁在一起就能使用

Yet even the best batteries will diminish daily,

即便是現在最棒的電池也會日漸衰涸

slowly losing capacity until they finally die.

慢慢地失去電量直到它們最終掛掉

So why does this happen,

為什麼會發生這種事呢？

以及電池是如何在剛開始 就存有這麼多電量呢？

and how do our batteries even store so much charge in the first place?

It all started in the 1780s with two Italian scientists,

這一切起始於 1780-89 年間的 兩位義大利科學家 －

Luigi Galvani and Alessandro Volta,

「路易吉．賈法尼」 以及「亞歷山卓．伏打」

and a frog.

還有一隻青蛙

Legend has it that as Galvani was studying a frog's leg,

據說當賈法尼正在研究青蛙的大腿時

he brushed a metal instrument up against one of its nerves,

他把金屬儀器輕碰上蛙腿的一條神經

making the leg muscles jerk.

使得蛙腿肌肉抽動

Galvani called this animal electricity,

賈法尼稱其為「動物電」

believing that a type of electricity was stored in the very stuff of life.

他認為有一種電力型態 被儲存在生命體裡面

But Volta disagreed,

但是伏打不認同

arguing that it was the metal itself that made the leg twitch.

他指出是金屬本身使得蛙腿抽搐

The debate was eventually settled with Volta's groundbreaking experiment.

該爭論最終平息於 「伏打」開創性的實驗下

He tested his idea with a stack of alternating layers of zinc and copper,

他用了一堆交疊的鋅片與銅片 來驗證他的想法

separated by paper or cloth soaked in a salt water solution.

用被鹽水試劑浸濕的紙或布料隔開

What happened in Volta's cell is something chemists now call oxidation and reduction.

在伏打的電池裡所發生的是化學家 現在稱做「氧化、還原」的現象

The zinc oxidizes, which means it loses electrons,

鋅片氧化代表它失去了電子

which are, in turn, gained by the ions in the water in a process called reduction,

該電子接著被水中的離子在叫做 「還原」的過程中取得

producing hydrogen gas.

而產生出氫氣

Volta would have been shocked to learn that last bit.

伏打要是得知最後這一部分 也會感到吃驚的

He thought the reaction was happening in the copper,

他以為該反應發生在銅片裡面

rather than the solution.

而不是鹽水試劑中

None the less, we honor Volta's discovery today

儘管如此我們仍透過把電力的 標準單位命名為「伏特」

by naming our standard unit of electric potential "the volt."

來紀念伏打的發現

This oxidation-reduction cycle creates a flow of electrons between two substances

該「氧化、還原」循環 在這兩種物質之間產生電流

and if you hook a lightbulb or vacuum cleaner up between the two,

如果你掛個燈泡或是吸塵器 在兩種物質間的上方

you'll give it power.

你將會給它電力

Since the 1700s, scientists have improved on Volta's design.

自從十八世紀以來科學家們已經在 伏打的設計上做了改進

They've replaced the chemical solution with dry cells filled with chemical paste,

他們以裝填了化學粘料的乾電池 取代了化學試劑

but the principle is the same.

不過原理是一樣的

A metal oxidizes, sending electrons to do some work

一端的金屬氧化送出電子

before they are regained by a substance being reduced.

在它們被另一項物質 重新取得還原前來做些「功」

But any battery has a finite supply of metal,

但是任何電池的金屬量是有限的

and once most of it has oxidized, the battery dies.

一旦大部分的金屬已經氧化掉了 該電池也就掛點了

So rechargeable batteries give us a temporary solution to this problem

所以充電電池給了我們一個 針對這問題的短暫解決方法

by making the oxidation-reduction process reversible.

透過讓「氧化、還原」過程 能倒過頭來做的

Electrons can flow back in the opposite direction

電子可以憑藉電力的運用來流回相反方向

with the application of electricity.

Plugging in a charger draws the electricity from a wall outlet

插上充電器從牆上的插座把電力導出

that drives the reaction to regenerate the metal,

帶動反應來讓金屬再生

making more electrons available for oxidation the next time you need them.

使得你在下次需要它們的時候 氧化時能有更多電子可取得

But even rechargeable batteries don't last forever.

但就算是充電電池也沒辦法永保安康

Over time, the repetition of this process causes imperfections

長時間下來重複這個過程

造成金屬的表面有瑕疵、不規則 使它不能好好地氧化、

and irregularities in the metal's surface that prevent it from oxidizing properly.

The electrons are no longer available to flow through a circuit

電子不再能夠在迴路上流動

and the battery dies.

這個電池就掛點了

Some everyday rechargeable batteries

有些每天充電的電池

will die after only hundreds of discharge-recharge cycles,

只做幾百回充、放電循環後就會掛點掉

while newer, advanced batteries can survive and function for thousands.

同一時間比較新、先進的電池 可以撐過運行數千回的循環

Batteries of the future may be light, thin sheets

未來的電池可能是既輕又薄的薄片

that operate on the principles of quantum physics

在量子物理學的原理下運作

and last for hundreds of thousands of charge cycles.

而且撐過幾十萬回的充電循環

But until scientists find a way to take advantage of motion

不過直到科學家們找到方法 利用動能來讓你的手機電池充電以前

to recharge your cell battery, like cars do,

or fit solar panels somewhere on your device,

就像汽車的動能回充

或是把太陽能板裝進 你的電子裝置的某處以前

plugging your charger into the wall,

把你的充電器插進牆上的插座

rather than expending one battery to charge another

而不是耗費一個電池去充另外一個

is your best bet to forestall that fatal "bleep."

是你預先防止要命的「嗶」聲最好方法