课程咨询
托福培训

扫码免费领资料

内含托福全科备考资料

更有免费水平测试及备考规划

托福培训

扫码关注掌握一手留学资讯

回复XDF免费水平测试

托福听力练习-科学美国人60秒:可充电电池

2017-03-30 08:41:00来源:科学美国人60秒

点击查看>>科学美国人60秒音频:可充电电池

  科学美国人60秒听力练习:可充电电池

  科学美国人60秒英文文本

  Ever wonder why some expensive lithium ion batteries go dead after a certain number of charges? Mystery solved. Scientists now know the culprit is nickel, which is added during the manufacturing process to increase the battery's capacity.

  At the atomic level, in the many batteries that use lithium-nickel-manganese oxide, the manganese and oxygen atoms form orderly rows. During normal operation, lithium ions zip up and down the empty channels in between the rows to charge or discharge the battery.

  Researchers thought that the added nickel atoms were distributed evenly among the rows. However, a team led by scientists at Pacific Northwest National Laboratories has new high-resolution 3-D images that tell a different story. Rather than being evenly distributed, the nickel clumps together and blocks the channels, preventing the flow of ions and keeping the battery from charging. The research is published in the journal Nano Letters.

  The nickel blockage appears to be a result of the manufacturing process. So identifying and controlling manufacturing conditions may one day make batteries last longer. And keep your current current.

  中文翻译请点击下一页

本文关键字: 托福听力 科学美国人

托福辅导

关注新东方在线托福

托福机经·Official题目练习

考前重点突破·听说读写海量资料

更多资料
更多>>
更多内容

免费获取托福备考大礼包

微信扫描下方二维码 立即领取

托福辅导
更多>>
更多公益讲座>>
更多>>
更多资料