经济学人下载:让乌龟和兔子交配(3)

According to a paper its inventors published recently in Nature Communications, the Graz cell's performance exceeds that of a Li-ion battery. It is able, for example, to cope with up to 1m charge and discharge cycles, says Qamar Abbas, a member of the team. A Li-ion equivalent might be expected to manage a couple of thousand cycles. 

根据其发明者最近发表在《自然通讯》上的一篇论文，格拉茨电池的性能超过了锂离子电池。例如，研究小组成员卡马尔·阿巴斯说，它能够应付高达100万次的充放电循环。锂离子当量的电池可以运行几千次循环。

Both Skeleton and the Graz group, then, are taking modified supercapacitor architecture and adding some bespoke electrochemistry. By contrast, although the offering from NAWATechnologies does indeed also employ modified supercapacitor plates as its electrodes, it uses tried and trusted Li-ion ingredients for the chemical donkey work. 

于是，骨架和格拉茨团队都采用了改良的超级电容器结构，并添加了一些定制的电化学元素。相比之下，虽然NAWATechnologies公司提供的产品确实也使用了改良的超级电容器板作为电极，但它使用了经过验证的锂离子成分来进行化学辅助工作。

Like Skeleton, NAWA already manufactures supercapacitors. The plates for these are created using a process which the firm calls VACNT(vertically aligned carbon nanotubes). This arranges those tubes in an array that resembles, in miniature, the bristles on a brush. Extreme miniature. A square centimetre contains about 100bn of them, all standing to attention. That greatly increases the surface area available to hold an electric charge. 

NAWA和骨架一样，也在生产超级电容器。该公司使用一种叫做VACNT(垂直排列碳纳米管)的工艺制造了这些平板，将这些管子像微型刷子的刷毛一样进行排列。极端的缩影。每平方厘米大约有1000亿条管子竖着立正，这大大增加了可容纳电荷的表面积。

To adapt VACNT plates to operate also as battery-like electrodes, NAWA's engineers have thinned the nanotube forest to make room for coatings of the chemicals which batteries employ for their reactions, and also for the movement of lithium ions into and out of the spaces between the tubes. This freedom of movement, the company reckons, will boost the arrangement's power density by a factor of ten. 

为了使VACNT板也能作为类似电池的电极使用，NAWA的工程师对纳米管进行了细化，为电池进行化学反应所使用的化学涂层腾出空间，为锂离子进出奈米管之间的空间腾出空间。该公司估计，这种自由移动将使这种装置的功率密度提高10倍。

To start with, the nanotubes of the invention's cathode (the positive electrode in a battery) will be coated with nickel, manganese and cobalt, a mixture already widely used to make such cathodes. Conventional anodes (the negative electrodes) are already carbon based, so using that element in the form of nanotubes is not a big departure. Other, less commercially developed battery chemistries should, though, also work with VACNT electrodes. These include lithium-sulphur and lithium-silicon, both of which have the potential to increase energy densities. 

首先，该发明的阴极(电池中的正极)的纳米管将被镀上镍、锰和钴，一种已经广泛用于制造此类阴极的混合体。传统的阳极(负极)已经是碳基的，所以使用碳纳米管形式的元素并没有太大的差异。尽管如此，其他未被商业化开发的电池化学物质也应该适用于VACNT电极。其中包括锂-硫和锂-硅，这两种物质都有可能增加能量密度。

Silicon is particularly promising, but it swells as it absorbs ions, and that can rupture a battery. The thicket of nanotubes in a VACNT electrode should operate like a cage to keep the silicon in check, says Pascal Boulanger, a physicist who helped found NAWA in 2013. The new electrode material could also be used with solid rather than liquid electrolytes, to make "solid-state" batteries. These are powerful and robust, but are proving tricky to commercialise.

硅的前景极其光明，但它会在吸收离子的过程中膨胀，这可能会损坏电池。2013年协助发现NAWA的物理学家帕斯卡尔·布朗热称VACNT电极中错综复杂的纳米管就像笼子一样控制着硅。这种新的电极材料也可以用于固体电解质(非液体电解质)以制造“固态”电池。这些技术既强大又稳健，但商业化却很棘手。