【科技】科學家如何利用水泥為你的房子發電？_風聞

【來源龍騰網】

正文原創翻譯：

On a laboratory bench in Cambridge, Massachusetts, a stack of polished cylinders of black-coloured concrete sit bathed in liquid and entwined in cables. To a casual observer, they aren’t doing much. But then Damian Stefaniuk flicks a switch. The blocks of human-made rock are wired up to an LED – and the bulb flickers into life.

在馬薩諸塞州劍橋市的一個實驗室工作台上，一堆拋光的黑色混凝土圓柱體浸泡在液體中，並纏繞着電纜。它們乍看起來用處不大，但當達米安·斯泰法尼烏克按下開關時，這些人造石塊被電線連接到一隻LED燈上，燈泡瞬間點亮了。

“At first I didn’t believe it,” says Stefaniuk, describing the first time the LED lit up. “I thought that I hadn’t disconnected the external power source, and that was why the LED was on.

“起初我不相信”，斯泰法烏克在回憶LED燈被第一次點亮時説道，“我以為是自己沒有斷開外部電源，所以LED燈亮了”。

“It was a wonderful day. We invited students, and I invited professors to see, because at first they didn’t believe that it worked either.”

“那天真是太棒了，我們邀請了學生和教授前來參觀，因為他們一開始也不相信這種事情”。

The reason for the excitement? This innocuous, dark lump of concrete could represent the future of energy storage.

心情激動的原因？這種無害的黑色混凝土塊可能預示着能源存儲的未來。

The promise of most renewable energy sources is that of endless clean power, bestowed on us by the Sun, wind and sea.

大多數可再生能源的前景是太陽、風、海洋賦予我們的用之不竭的清潔能源。

Yet the Sun isn’t always shining, the wind isn’t always blowing, and still waters do not, in megawatt terms, run deep. These are energy sources that are intermittent, which, in our energy-hungry modern world, poses a problem.

但陽光不會一直照耀，風不會一直吹拂，靜水在兆瓦級發電能力上並不強勁。這些間歇性能源給我們這個能源需求旺盛的現代世界帶來一個難題。

It means that we need to store that energy in batteries. But batteries rely on materials such as lithium, which is in far shorter supply than is likely to be needed to meet the demand created by the world’s quest to decarbonise its energy and transport systems. There are 101 lithium mines in the world, and economic analysts are pessimistic about the ability of these mines to keep up with growing global demand. Environmental analysts note that lithium mining uses a lot of energy and water, which nibble away at the environmental benefits of switching to renewable energy sources in the first place. The processes involved in extracting lithium can also sometimes lead to toxic chemicals leaking into local water supplies.

這意味着我們需要將這些能源儲存在蓄電池中。但蓄電池依賴於鋰等材料，其供應量遠遠低於潛在需求，無法滿足全球能源和運輸系統的脱碳需要。全球有101座鋰礦，經濟分析師對它們能否滿足日益增長的全球需求持悲觀態度。環境分析師指出，鋰礦開採消耗大量的能源和水，一開始就削弱了向可再生能源轉型所獲得的環境效益。鋰的提取工藝有時產生有毒的化學物質，泄漏到當地水源中。

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Despite some new discoveries of lithium reserves, the finite supply of this material, the over-reliance on just a handful of mines around the world and its environmental impact have driven the search for alternative battery materials.

儘管發現了新的鋰礦資源，但這種材料的有限供應，對全球少數幾座鋰礦的過度依賴，以及造成的環境影響促使人們尋找電池替代材料。

This is where Stefaniuk and his concrete come in. He and his colleagues at Massachusetts Institute of Technology (MIT) have found a way of creating an energy storage device known as a supercapacitor from three basic, cheap materials – water, cement and a soot-like substance called carbon black.

這正是斯泰法烏克及其混凝土派上用場的地方。他和麻省理工學院的同事們研究出一種方法，利用三種便宜的基礎材料——水、水泥、名為碳黑的煙灰狀物質，製造出一種名為超級電容器的儲能裝置。

Supercapacitors are highly efficient at storing energy but differ from batteries in some important ways. They can charge much more quickly than a lithium ion battery and don’t suffer from the same levels of degradation in performance. But supercapacitors also release the power they store rapidly, making them less useful in devices such as mobile phones, laptops or electric cars where a steady supply of energy is needed over an extended period of time.

超級電容器的儲能效率很高，但在一些重要方面與蓄電池不同。超級電容器的充電速度遠快於鋰電池，並且性能衰減不像鋰電池那樣嚴重。不過超級電容器的放電速度也很快，所以它們在手機、筆記本電腦、電動汽車等設備中的用處不大，因為這些設備需要獲得長時間和穩定的能量供應。

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Yet according to Stefaniuk, carbon-cement supercapacitors could make an important contribution to efforts to decarbonise the global economy. “If it can be scaled up, the technology can help solve an important issue – the storing of renewable energy,” he says.

但斯泰法尼烏克表示，碳-水泥超級電容器可以為全球經濟的脱碳事業做出重要貢獻。他説：“如果能夠擴大規模，這項技術有助於解決一大難題——儲存可再生能源”。

He and his fellow researchers at MIT and Harvard University’s Wyss Institute for Biologically Inspired Engineering, envisage several applications for their supercapacitors.

他與麻省理工學院、哈佛大學懷斯生物啓發工程研究所的同事研究員們，設想了他們的超級電容器的多種用途。

One might be to create roads that store solar energy and then release it to recharge electric cars wirelessly as they drive along a road. The rapid release of energy from the carbon-cement supercapacitor would allow vehicles to get a rapid boost to their batteries. Another would be as energy-storing foundations of houses – “to have walls, or foundations, or columns, that are active not only in supporting a structure, but also in that energy is stored inside them”, says Stefaniuk.

一種用途是建造能夠儲存太陽能的公路，通過釋放太陽能為沿途行駛的車輛進行無線充電。碳-水泥超級電容器的快速放電可以使車輛的蓄電池快速充電。另一種用途是作為房屋的儲能基礎——“牆體、地基、柱子不僅起到支撐房屋的作用，還能將能量儲存在裏面”，斯泰法尼烏克説道。

But it is still early days. For now, the concrete supercapacitor can store a little under 300 watt-hours per cubic metre – enough to power a 10-watt LED lightbulb for 30 hours.

但現在為時尚早。目前，這種混凝土超級電容器每立方米的儲能略低於300瓦時，足以為一隻10瓦的LED燈泡供電30小時。

The power output “may seem low compared to conventional batteries, [but] a foundation with 30-40 cubic metres (1,060-1,410 cubic feet) of concrete could be sufficient to meet the daily energy needs of a residential house”, says Stefaniuk. “Given the widespread use of concrete globally, this material has the potential to be highly competitive and useful in energy storage.”

它的輸出功率“可能低於傳統蓄電池，但30-40 立方米（1060-1410 立方英尺）的混凝土地基足以滿足一户住宅的日常能源需求”，斯泰法尼烏克説道。“考慮到全球廣泛使用混凝土，這種材料在儲能方面可能具有很高的競爭力和實用價值”。

Stefaniuk and his colleagues at MIT initially proved the concept by creating cent-sized 1V supercapacitors from the material before connecting together in series to power a 3V LED. They have since scaled this up to produce a 12V supercapacitor. Stefaniuk has also been able to use larger versions of the supercapacitor to power a handheld games console.

斯泰法尼烏克和他在麻省理工學院的同事初步證明了這一概念，他們利用這種材料製造了多個美分硬幣大小的1V超級電容器，將它們串聯起來為一隻3V LED燈泡供電。他們隨後提升了性能，製造出12V的超級電容器。斯泰法尼烏克還能夠利用更大的超級電容器為掌上游戲機供電。

And the research team are now planning to build larger versions, including one up to 45 cubic metres (1,590 cubic feet) in size that would be able store around 10kWh of energy needed to power to power a house for a day.

目前，研究團隊正打算製造更大的超級電容器，包括一個體積達45立方米（約 1590立方英尺）的電容器，能夠儲存大約10千瓦時的能源，足以為一座房屋供電一天。

The supercapacitor works due to an unusual property of carbon black – it is highly conductive. This means that when carbon black is combined with cement powder and water, it makes for a kind of concrete that is full of networks of conductive material, taking a form that resembles ever-branching, tiny roots.

超級電容器的工作原理是基於碳黑的一個獨特特性：高導電性。這意味着當碳黑、水泥粉、水混合時會形成一種混凝土，裏面佈滿了由導電材料構成的網絡，其形態類似於不斷分叉的微小根系。

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Capacitors are formed of two conductive plates with a membrane in between them. In this case, both plates are made of the carbon black cement, which were soaked in an electrolyte salt called potassium chloride.

電容器由兩塊導電板組成，中間有一層薄膜。超級電容器的兩塊導電板由碳黑水泥製成，並浸泡在一種名為氯化鉀的電解質鹽中。

When an electric current was applied to the salt-soaked plates, the positively-charged plates accumulated negatively charged ions from the potassium chloride. And because the membrane prevented charged ions from being exchanged between the plates, the separation of charges created an electric field.

當電解質鹽中的導電板被施加電流時，氯化鉀中的負離子會聚集到正極電板上，由於薄膜阻止了帶電離子在電板之間交換，電荷的分離產生了電場。

As supercapacitors can accumulate large amounts of charge very quickly, it could make the devices useful for storing excess energy produced by intermittent renewable sources such as the wind and solar. This would take the pressure off the grid at times when the wind is not blowing, nor the Sun shining. As Stefaniuk says, “A simple example would be an off-grid house powered by solar panels: using solar energy directly during the day and the energy stored in, for example, the foundations during the night.”

由於超級電容器能夠快速地積累大量電荷，因此可用於儲存風能和太陽能等間歇性可再生能源產生的過剩能量，從而在沒有風或陽光的時候緩解電網的壓力。正如斯泰法尼烏所言，“舉一個簡單的例子，由太陽能電池板供電的離網房屋：白天直接使用太陽能，晚上使用儲存在地基中的能源”。

Supercapacitors are not perfect. Existing iterations discharge power quickly, and are not ideal for steady output, which would be needed to power a house throughout the day. Stefaniuk says he and his colleagues are working on a solution that would allow their carbon-cement version to be tuned by adjusting the mixture, but they will not disclose the details until they have finalised the tests and published a paper.

超級電容器並不完美。現有設計的放電速度很快，不適合房屋全天供電所需要的穩定輸出。斯蒂芬尼烏克表示，他和同事們正在研究一種解決方案，通過調整混合物的配比來優化碳-水泥超級電容器，但他們在完成測試和發表論文之前不會透露細節。

There could be other issues to overcome too – adding more carbon black allows the resulting supercapacitor to store more energy, but it also makes the concrete slightly weaker too. The researchers say any uses that have a structural role to play as well as energy storage would need to find an optimum mix of carbon black.

可能還有其他問題有待於克服——增加炭黑可以使超級電容器儲存更多能源，但也會使混凝土變得略微脆弱。研究人員表示，任何兼具結構支撐與儲能的用途都需要找到炭黑的最佳配比。

And while carbon-cement supercapacitors could help to reduce our reliance on lithium, they come with their own environmental impact. Cement production is responsible for 5-8% of carbon dioxide emissions from human activity globally, and the carbon-cement needed for the supercapacitors would need to be freshly made rather than retrofitted in existing structures.

雖然碳-水泥超級電容器有助於我們減少對鋰的依賴，但它也會對環境造成影響。水泥生產佔全球人類活動二氧化碳排放量的5-8% ，超級電容器需要全新生產的碳-水泥，而不是對現有建築的材料加以改良。

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Nevertheless, it seems to be a promising innovation, says Michael Short, who leads the Centre for Sustainable Engineering at Teesside University in the UK. The research “opens many interesting potential avenues around the use of the built environment itself as an energy storage medium”, he says. “As the materials are also commonplace and the manufacture relatively straightforward, this gives a great indication that this approach should be investigated further and could potentially be a very useful part of the transition to a cleaner, more sustainable future.”

儘管如此，這看起來是一項有前途的創新，英國蒂賽德大學可持續工程中心的負責人邁克爾·肖特説道。這項研究“對於如何利用建成環境作為儲能介質開闢了許多有趣的潛在途徑”，他説道。“由於這些材料都很常見，製造起來相對簡單，這充分表明這種方法值得進一步研究，並且可能在向更清潔、更可持續的未來轉型中發揮重要作用”。