How batteries work - Adam Jacobson

Translator: Sylvia He Reviewer: Alan Watson

You probably know the feeling.

你可能經歷過當你嘅手機「嗶」一聲後

Your phone utters its final plaintive "bleep"

and cuts out in the middle of your call.

部電話就冇電囉

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

呢個時候你都想掟嚿電

than singing its praises,

多過欣賞嚿電嘅奧妙

but batteries are a triumph of science.

之但係，電池係科學嘅勝利

They allow smartphones and other technologies to exist

冇佢，好多科技產品，譬如智能手機

without anchoring us to an infernal tangle of power cables.

就要長期插住電掣

Yet even the best batteries will diminish daily,

但係最好嘅電池都會日漸遞減

slowly losing capacity until they finally die.

慢慢冇曬電量，直到殆盡

So why does this happen,

點解會咁？

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

點解電池一開始有咁多電？

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

一切源於 1780 年代兩位意大利科學家

Luigi Galvani and Alessandro Volta,

路易吉．賈法尼 以及亞歷山卓．伏特

and a frog.

仲有隻田雞

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

據說賈法尼喺度研究田雞嘅大髀

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

佢用金屬工具點咗田雞髀嘅一條神經

making the leg muscles jerk.

使到田雞隻腳彈咗一下

Galvani called this animal electricity,

賈法尼稱其之「動物電」

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

佢認為有種電儲存喺生命體裡面

But Volta disagreed,

不過伏特唔認同

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

佢話金屬本身使到田雞髀抽搐

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

收尾，伏特一個開創性嘅實驗 平息咗呢個爭論

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

佢用一堆交錯疊埋嘅鋅片同銅片

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

鋅片同銅片之間 用鹽水濕過 嘅紙或者布料隔開

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

伏特嘅電池裡邊發生 「氧化、還原」嘅化學現象

The zinc oxidizes, which means it loses electrons,

鋅片氧化並失去電子

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

電子被水裡邊嘅離子攞咗

即係還原反應

producing hydrogen gas.

並產生氫氣

Volta would have been shocked to learn that last bit.

伏特見到啲氫氣好意外

He thought the reaction was happening in the copper,

佢以為呢個反應發生喺銅片裡邊

rather than the solution.

而唔係喺鹽水裡邊

None the less, we honor Volta's discovery today

即使係咁

我哋仲係將電勢嘅單位

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

命名為「伏特」來紀念佢

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

「氧化、還原」循環 令電流產生喺兩種物質之間

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

如果你將燈泡或者吸塵機連接落電路度

you'll give it power.

佢哋會有電

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

十八世紀以來 科學家改良咗伏特嘅設計

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

佢哋以裝滿化學漿嘅乾電池 取代咗化學溶液

but the principle is the same.

但原理仲係一樣

A metal oxidizes, sending electrons to do some work

一端嘅金屬氧化送出電子

before they are regained by a substance being reduced.

另一端物質因為接收電子而還原

But any battery has a finite supply of metal,

但係任何電池嘅金屬數目都有限

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

金屬一旦全部氧化，電池就殆盡

So rechargeable batteries give us a temporary solution to this problem

充電式電池可以扭轉氧化還原反應

by making the oxidation-reduction process reversible.

來暫時解決電池殆盡嘅問題

Electrons can flow back in the opposite direction

電流可以逆轉電子嘅流向

with the application of electricity.

將叉電器插落插蘇度

Plugging in a charger draws the electricity from a wall outlet

that drives the reaction to regenerate the metal,

電流會令金屬重生

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

令到有電子可以供氧化

But even rechargeable batteries don't last forever.

不過，充電式電池都會有殆盡嘅一日

Over time, the repetition of this process causes imperfections

充電嘅過程並唔完美

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

金屬嘅表面嘅唔平滑會影響氧化反應

The electrons are no longer available to flow through a circuit

使到電子冇法喺個電路度循環

and the battery dies.

咁個電池就殆盡嘞

Some everyday rechargeable batteries

所以啲充電式電池

will die after only hundreds of discharge-recharge cycles,

充電幾百次之後就唔得嘞

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

新型嘅充電式電池可以充幾千次電

Batteries of the future may be light, thin sheets

未來嘅電池會更輕更薄

that operate on the principles of quantum physics

同用量子力學嘅原理運作

and last for hundreds of thousands of charge cycles.

可以充電數十萬次

But until scientists find a way to take advantage of motion

但係如果科學家 移植唔到充電架車嘅方法

to recharge your cell battery, like cars do,

or fit solar panels somewhere on your device,

或者安個太陽能電池板 喺個電話度

plugging your charger into the wall,

插入牆叉部電話

rather than expending one battery to charge another

比起用流動充電器充電

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

會更有效保護電池免受殆盡