科学家研发出可将锂电池充电效率与容量提升十倍

科学家研发出可将锂电池充电效率与容量提升十倍的突破性新技术


其实我们并不是很常追随一些电池技术的进展，但说到开创性的大突破的话，我们可绝对不会错过！这个由西北大学工程师所研发出来最新技术，宣称可以让锂电池的充电效率与容量得到十倍的大幅度成长。教授 Harold Kung 与他的研究团队表示，此电池技术的关键在于锂离子在石墨烯层间的流动状态 -- 离子在其中的流动速度很直接的影响到充电速度的快慢。而为了加速流动速度，他们研究出改变石墨烯排列，使其成为数百万个只有 10 到 20nm 大小的蜂槽型柱状体，制造出更适合锂离子流动的「快速快捷方式」。也因为如此，Kung 教授的团队也达成整整缩短 1/10 电池充电时间的成绩，不过！这还只是充电速度的部份而已。

这群科学家更将电池的蓄电量也同时往上提升，他们研究将小群的硅（Silicon）置入石墨烯层之间，达成提升电池内部锂离子的密度的效果。归功于石墨烯所提供高延展特性，这样的技术突破也使聚集在电极附近锂离子更多，也因此使因为硅膨胀所造成的老问题获得解决。至于成果如何？如同标题一样威猛，这颗电池在完全充满电之后，将可整整维持一周的使用时间，Kung 也表示「如今我们终于即将在双方面都得到最佳表现」。因为硅以及技术的进步，我们获得更高的蓄电密度，甚至就算硅团簇（Silicon Clusters）分离也不会造成硅的消失。不过他说的是「即将得到」，那么可见此技术仍有尚待改进之处 -- 得到大幅改进的充电速度与电池容量，将会在 150 次的充电次数后使效率急剧下滑。但 Kung 也指出增加电池的充电保持（Charge Retention）能力将足以弥补这样的缺点 --「即使仍维持 150 次的充电次数表现，但寿命却可达一年或更久，更别说电池在此之后仍拥有现有锂电池的五倍效率。」Kung 在 BBC 的报导中这样说道。

原文：

It's not every day that we get to write about advancements in battery technology -- much less one as potentially groundbreaking as what a group of engineers at Northwestern University claim to have pulled off. In fact, Professor Harold Kung and his team say they've successfully managed to increase both the charging capacity and speed of lithium ion batteries by a factor of ten. The key, according to Kung, is the movement of the lithium ions nestled between layers of graphene. The speed at which these ions move across a battery's graphene sheets is directly related to how fast a device can recharge. To speed up this process, Kung decided to poke millions of tiny, 10-20nm-sized holes into a mobile battery's graphene layers, thereby providing the ions with a "shortcut" to the next level. As a result, Kung's perforated batteries were able to charge ten times faster than traditional cells, going from zero to hero in 15 minutes.

Not satisfied with that achievement alone, Kung and his squad then set about increasing their battery's charging capacity, as well. Here, they increased the density of lithium ions by inserting small clusters of silicon between each graphene slice. This approach allows more ions to gather at the electrode and, by taking advantage of graphene's malleable properties, avoids some of the silicon expansion problems that have plagued previous attempts at capacity enhancement. The result? A battery that can run on a single charge for more than a week. "Now we almost have the best of both worlds," Kung said. "We have much higher energy density because of the silicon, and the sandwiching reduces the capacity loss caused by the silicon expanding and contracting. Even if the silicon clusters break up, the silicon won't be lost." There is, however, a downside, as both charging capacity and speed sharply fell off after 150 charges. But as Kung points out, the increase in charge retention would more than make up for this shortcoming. "Even after 150 charges, which would be one year or more of operation, the battery is still five times more effective than lithium-ion batteries on the market today," he told the BBC. For more technical details, hit up the links below.