持久穩(wěn)定的固態(tài)鋰電池有突破了

Long-lasting, quick-charging batteries are essential to the expansion of the electric vehicle market, but today's lithium-ion batteries fall short of what's needed -- they're too heavy, too expensive and take too long to charge.

持久、快速充電的電池對(duì)電動(dòng)汽車(chē)市場(chǎng)的擴(kuò)張至關(guān)重要，但如今的鋰離子電池還不能滿(mǎn)足需要——它們太重、太貴、充電時(shí)間太長(zhǎng)。

For decades, researchers have tried to harness the potential of solid-state, lithium-metal batteries, which hold substantially more energy in the same volume and charge in a fraction of the time compared to traditional lithium-ion batteries.

幾十年來(lái)，研究人員一直試圖利用固態(tài)鋰金屬電池的潛力，與傳統(tǒng)的鋰離子電池相比，固態(tài)鋰金屬電池在相同體積下能儲(chǔ)存更多的能量，充電時(shí)間更短。

"A lithium-metal battery is considered the holy grail for battery chemistry because of its high capacity and energy density," said Xin Li, Associate Professor of Materials Science at the Harvard John A. Paulson School of Engineering and Applied Science (SEAS). "But the stability of these batteries has always been poor."

“鋰金屬電池因其高容量和高能量密度而被認(rèn)為是電池化學(xué)的圣杯，但它們的穩(wěn)定性一直很差。”哈佛大學(xué)SEAS學(xué)院材料科學(xué)副教授李鑫(Xin Li)表示。

Now, Li and his team have designed a stable, lithium-metal solid state battery that can be charged and discharged at least 10,000 times -- far more cycles than have been previously demonstrated --- at a high current density. The researchers paired the new design with a commercial high energy density cathode material.

近日，李鑫和他的團(tuán)隊(duì)設(shè)計(jì)了一種穩(wěn)定的鋰金屬固態(tài)電池，可以在高電流密度下進(jìn)行至少10000次充放電，遠(yuǎn)超之前演示的循環(huán)次數(shù)。研究人員將這種新設(shè)計(jì)與一種商用的高能量密度陰極材料配對(duì)。

This battery technology could increase the lifetime of electric vehicles to that of the gasoline cars -- 10 to 15 years -- without the need to replace the battery. With its high current density, the battery could pave the way for electric vehicles that can fully charge within 10 to 20 minutes.

這種電池技術(shù)可以將電動(dòng)汽車(chē)的壽命延長(zhǎng)至汽油汽車(chē)的壽命——10至15年，而無(wú)需更換電池。由于其高電流密度，該電池可以在10-20分鐘內(nèi)為電動(dòng)汽車(chē)充滿(mǎn)電。The research is published in Nature.

這項(xiàng)研究發(fā)表在《自然》雜志上。

The big challenge with lithium-metal batteries has always been chemistry. Lithium batteries move lithium ions from the cathode to the anode during charging. When the anode is made of lithium metal, needle-like structures called dendrites form on the surface. These structures grow like roots into the electrolyte and pierce the barrier separating the anode and cathode, causing the battery to short or even catch fire.

鋰金屬電池的最大挑戰(zhàn)一直是化學(xué)。鋰電池在充電過(guò)程中將鋰離子從陰極轉(zhuǎn)移到陽(yáng)極。當(dāng)陽(yáng)極由金屬鋰制成時(shí)，表面形成針狀結(jié)構(gòu)，稱(chēng)為枝晶(dendrites)。這些結(jié)構(gòu)像根一樣生長(zhǎng)在電解液中，刺穿分隔陽(yáng)極和陰極的屏障，導(dǎo)致電池短路甚至起火。

To overcome this challenge, Li and his team designed a multilayer battery that sandwiches different materials of varying stabilities between the anode and cathode. This multilayer, multimaterial battery prevents the penetration of lithium dendrites not by stopping them altogether but rather by controlling and containing them.

為了克服這一挑戰(zhàn)，李和他的團(tuán)隊(duì)設(shè)計(jì)了一種多層電池，在陽(yáng)極和陰極之間夾有不同穩(wěn)定性的不同材料。這種多層、多材料電池不是完全阻止鋰枝晶，而是通過(guò)控制和容納它們來(lái)防止鋰枝晶的滲透。

Think of the battery like a BLT sandwich. First comes the bread -- the lithium metal anode -- followed by lettuce -- a coating of graphite. Next, a layer of tomatoes -- the first electrolyte -- and a layer of bacon -- the second electrolyte. Finish it off with another layer of tomatoes and the last piece of bread -- the cathode.

你可以把電池想象成一個(gè)三明治：首先是“面包”(鋰金屬陽(yáng)極)，然后是“生菜”(一層石墨)。接下來(lái)，夾一層“西紅柿”(第一種電解質(zhì))、一層“培根”(第二種電解質(zhì))。最后再來(lái)一層“西紅柿”和最后一塊面包——陰極。

The research was supported by Dean's Competitive Fund for Promising Scholarship at Harvard University and Harvard Data Science Initiative Competitive Research Fund. Further developments of this project will be supported by Harvard Physical Sciences and Engineering Accelerator Award and Harvard Climate Change Solutions Fund.

這項(xiàng)研究得到了哈佛大學(xué)院長(zhǎng)獎(jiǎng)學(xué)金競(jìng)爭(zhēng)基金和哈佛數(shù)據(jù)科學(xué)倡議競(jìng)爭(zhēng)研究基金的支持。該項(xiàng)目的進(jìn)一步發(fā)展將得到哈佛物理科學(xué)與工程加速器獎(jiǎng)和哈佛氣候變化解決方案基金的支持。