2017年托福独立听力备考考点练习题:利用藻类改进电池

托福考试网 鲤鱼小编 更新时间:2017-04-21

   从褐藻中提炼的褐藻胶可以帮助稳定硅电极,以取代石墨电极,来生产质量更好,价格更低的电池。Cynthia Graber 报导。
  Common batteries are electrochemical cells. And they may get better thanks to living cells: the multicellular organism called brown algae.
  Lithium ion batteries include a binder. It holds the graphite nanoparticles that serve as the anode. The binder isn’t active, but researchers say it’s crucial in the battery’s stability. In theory, a silicon anode would make a better battery than graphite, but it’s not stable. Cracks form, and the battery degrades. The researchers thought—could a silicon anode succeed with a better binder?
  Seawater has a high concentration of ions, much like the battery’s electrolyte. So the researchers thought that an organism that survives in seawater might provide a natural binder. They tested alginate from brown algae. And it provided such an effective binder for silicon nanoparticles that the system didn’t degrade. The result? A battery that can store more energy, is less expensive, can last longer and wouldn’t use as many toxic chemicals in the manufacturing.
  The research is online in Science Express, in advance of publication in the journal Science. [Igor Kovalenko et al., "A Major Constituent of Brown Algae for Use in High-Capacity Li-Ion Batteries"]
  The scientists will refine their alginate efforts, in the hope that fast-growing brown algae can help contribute to our fast-growing battery economy.
  —Cynthia Graber
  科学美国人60秒中文翻译:
  普通电池是电气化的细胞。并且它们会因有生命的细胞,一种叫做褐藻的多细胞生物,而使其质量变得更好。
  锂电池内含粘结剂。它能固定住石墨的纳米颗粒来形成电极。粘结剂没有活性,但研究人员称它在保持电池的稳定性方面起着决定性的作用。理论上,硅电极比石墨电极更适合生产电池,但硅电极不够稳定。一旦产生裂缝,电池的质量就会下降。研究人员想--如果有更好的粘结剂,硅电极能否用于电池的实际生产呢?
  海水包含高浓度的离子,非常类似于电池的电解液。所以研究人员认为,海洋中的有机物可能会提供更好的粘结剂。他们测试了从蓝藻中得到的褐藻胶。它为硅的纳米颗粒提供了非常好的粘结剂,并且系统的质量并未下降。这个实验的结果?更好的电池产生了,它能储存更多能量,更廉价,持续时间更长,而且比传统电池生产技术使用更少的有毒化学物质。
  这个研究结果的在线版发布在《Science Express》,提前于《Science》。[Igor Kovalenko et al, A Major Constituent of Brown Algae for Use in High-Capacity Li-Ion Batteries]

  科研工作者将继续提高褐藻胶的精炼技术,他们希望快速生长的蓝藻能为同样快速增长的电池经济做出更大的贡献。 

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