雅思阅读 18: The Battery Made of Rust（用锈做的电池）

改编自 Form Energy / Futurist Speaker（2026年）。雅思阅读 Section 3 难度，约 1050 词。 素材来源：https://futuristspeaker.com/future-scenarios/the-battery-made-of-rust-that-could-change-everything/

Reading Passage

A. The most important battery innovation of the decade is not made of lithium, cobalt or any of the exotic materials that keep supply-chain strategists awake at night. It is made of iron, water and air. And it works by doing something every gardener understands: rust. This is no metaphor. Iron-air batteries literally rust to discharge energy and un-rust to recharge. In March 2026, Form Energy — a company operating from a former steel mill in Weirton, West Virginia — announced a 12-gigawatt-hour deal with an AI infrastructure company to power data centers starting in 2027. Three weeks earlier, Google and Xcel Energy had announced a 30-gigawatt-hour iron-air installation in Minnesota, the largest battery project ever announced. The technology is no longer a laboratory curiosity; it is being built at scale. The timing is not accidental. For a decade, advocates of renewable energy have argued that the missing piece was cheap, long-duration storage, and that without it grids would remain dependent on gas plants to cover their gaps. Iron-air arrived just as data centres, electrified transport and electrified heating all began pushing electricity demand sharply upward.

B. The chemistry is as simple as battery science gets. During discharge, iron pellets absorb oxygen from the air around them, exactly as iron rusts in the open air. That oxidation releases energy. To recharge, an electric current reverses the reaction, converting rust back into metallic iron and returning the oxygen to the atmosphere. The electrolyte is water-based and non-flammable, similar to that of an ordinary household battery. Iron is the fourth most abundant element in Earth's crust; water and air are free. There are no supply chains to South American salt flats, no cobalt mines in the Congo, no nickel geopolitics. The transition from fossil fuels to clean energy has, in many respects, been a shift from one set of supply-chain vulnerabilities to another. Iron-air largely escapes that trap. Critics of lithium-ion have long pointed out that every few hours of stored electricity requires a correspondingly small mountain of mined material. Iron-air inverts that logic: the raw material is cheap and abundant precisely because it has been rusting away, uselessly, since the atmosphere first turned oxygen-rich.

C. The number that distinguishes iron-air from every competing storage technology is 100. Lithium-ion excels at short-duration storage — two to four hours, the right length for storing daytime solar for the evening. But what happens when the wind dies across an entire region for three days, or a week of cloud cover blots out the sun? The renewable energy industry calls these "dark doldrums," and lithium-ion cannot bridge them economically: to cover three days you would need so many batteries that the cost becomes prohibitive. Iron-air can discharge continuously for up to 100 hours — not four, a hundred. Form Energy targets a system cost below twenty dollars per kilowatt-hour for multi-day storage, compared with 130 to 150 dollars for grid-scale lithium-ion. For long-duration applications, the technology is not marginally cheaper; it is an order of magnitude cheaper. The implication is that grids can be redesigned around weeks, not hours. A system that must survive a calm stretch no longer forces engineers to overbuild wind and solar so heavily that most of the output is wasted on the brightest afternoons. Instead, cheap long-duration storage acts as a reservoir, evening out the seasons rather than merely the evenings.

D. The trade-offs are real. Iron-air sacrifices efficiency for scale: of every five units of renewable energy stored, roughly two are returned, a round-trip efficiency of about 40 percent, compared with 85 to 95 percent for lithium-ion. The batteries are also heavy — a one-megawatt system requires half an acre of land — which means they will never power electric cars. They cannot be fast-charged; the electrochemical process is deliberately slow. And the air electrode must be protected from atmospheric carbon dioxide, which would otherwise react with the alkaline electrolyte and clog its pores over years of operation. Form Energy's solution, a specialised breathable barrier that blocks CO₂ while allowing oxygen through, appears to work in commercial installations, but it is an engineering problem that has been solved rather than one that never existed. The efficiency penalty is tolerable only because the stored fuel is so cheap. Wasting a large share of cheap, free sunlight is cheaper than wasting a smaller share of an expensive lithium-ion pack that must be mined, shipped and replaced every decade. Engineers describe it as trading electrons for dollars, and at grid scale the trade overwhelmingly favours the rust battery.

E. The applications are grid-scale, not portable. The first wave of deployments backs up wind and solar farms through multi-day lulls, replacing the gas "peaker" plants that utilities currently fire up when renewable generation dips. AI data centers are a particularly enthusiastic customer: they need reliable round-the-clock power that the existing grid cannot always deliver, and they consume enormous amounts of it. A planned installation in Maine, on the site of a converted paper mill, will be the world's largest battery by capacity when it comes online in 2028. Iron-air also passes safety tests that lithium-ion fails: its water-based electrolyte is non-flammable, and it produced no flame or thermal runaway in the UL9540A fire-safety standard. After a 2025 fire destroyed a California lithium-ion storage facility and forced the evacuation of a neighbourhood, the safety profile alone is a significant selling point for installations near populated areas. The future of grid storage, it seems, may be built from a material humanity has been using since the Iron Age — and rusting ever since. Whether the approach scales as cleanly as its advocates predict will depend on factors the demonstrations cannot yet show: how the breathable barriers perform after twenty years outdoors, whether local communities accept the acreage required, and whether competitors can undercut the cost target. Yet the direction of travel is clear. The material that civilisation once feared as decay is now being advertised as its most durable form of energy storage.

Questions 1-4

Choose the correct heading for paragraphs B, C, D and E from the list of headings below.

List of Headings i. The simplicity and abundance of the chemistry ii. How lithium-ion batteries work iii. Why 100 hours changes the economics of renewable storage iv. The trade-offs: efficiency, weight and engineering v. Where iron-air is actually being deployed vi. A history of rust research vii. Why iron-air batteries power electric cars

1. Paragraph B: ____
2. Paragraph C: ____
3. Paragraph D: ____
4. Paragraph E: ____

Questions 5-8

Choose the correct letter, A, B, C or D.

5. How does an iron-air battery discharge? A. It burns iron in a furnace. B. Iron pellets absorb oxygen and rust, releasing energy. C. It heats water to produce steam. D. It converts lithium ions into metallic iron.

6. Why is 100 hours significant? A. It matches the charging time of lithium-ion. B. It bridges multi-day periods of low renewable generation that lithium-ion cannot. C. It is the battery's expected lifetime. D. It is the time needed to install a system.

7. What is the round-trip efficiency of iron-air? A. 85–95 percent. B. About 40 percent. C. About 70 percent. D. 100 percent.

8. Why are iron-air batteries not used in electric vehicles? A. They are too expensive to manufacture. B. They are too heavy and cannot be fast-charged. C. They cannot be recharged. D. They produce toxic emissions.

Questions 9-13

Do the following statements agree with the claims of the writer?

Write:

• TRUE if the statement agrees with the information
• FALSE if the statement contradicts the information
• NOT GIVEN if there is no information on this

9. Iron is among the most abundant elements in Earth's crust.
10. Iron-air batteries are more efficient than lithium-ion.
11. A planned installation in Maine will be the largest battery by capacity when completed.
12. Iron-air batteries contain flammable liquid electrolytes.
13. Used iron-air batteries will be fully recycled at the end of their working life.

Questions 14-15

Complete the summary below using NO MORE THAN TWO WORDS from the passage.

Iron-air batteries work by (14) __________ to discharge and un-rusting to recharge. They are best suited to (15) __________-scale grid storage rather than portable use.

答案与解析

← 上一篇 | 返回雅思焦点 | 下一篇 →