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、快速充電的電池對電動汽車市場的擴張至關重要，但如今的鋰離子電池還不能滿足需要——它們太重、太貴、充電時間太長。

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，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存更多的能量，充電時間更短。

"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為是電池化學的圣杯，但它們的穩(wěn)定性一直很差。”哈佛大學SEAS學院材料科學副教授李鑫(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，李鑫和他的團隊設計了一種穩(wěn)定的鋰金屬固態(tài)電池，可以在高電流密度下進行至少10000次充放電，遠超之前演示的循環(huán)次數(shù)。研究人員將這種新設計與一種商用的高能量密度陰極材料配對。

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.

這種電池技術可以將電動汽車的壽命延長至汽油汽車的壽命——10至15年，而無需更換電池。由于其高電流密度，該電池可以在10-20分鐘內(nèi)為電動汽車充滿電。The research is published in Nature.

這項研究發(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。鋰電池在充電過程中將鋰離子從陰極轉(zhuǎn)移到陽極。當陽極由金屬鋰制成時，表面形成針狀結構，稱為枝晶(dendrites)。這些結構像根一樣生長在電解液中，刺穿分隔陽極和陰極的屏障，導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)，李和他的團隊設計了一種多層電池，在陽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，而是通過控制和容納它們來防止鋰枝晶的滲透。

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三明治：首先是“面包”(鋰金屬陽極)，然后是“生菜”(一層石墨)。接下來，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.

這項研究得到了哈佛大學院長獎學金競爭基金和哈佛數(shù)據(jù)科學倡議競爭研究基金的支持。該項目的進一步發(fā)展將得到哈佛物理科學與工程加速器獎和哈佛氣候變化解決方案基金的支持。