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房冲0814

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帖子: 11
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虫号: 2906134
注册: 2013-12-31
性别: GG
专业: 碳素材料与超硬材料

[求助] 求翻译修改，不胜感激，我翻译的觉得有好多问题

Ceaseless development of electronics leads to a point where all systems previously heavy and stationary can be produced as light and portable. This creates a new need – the need for a source of energy, compatible with the designed device. For the moment such a source could be lithium ion battery. Its advantages can be found both in the high volumetric and gravimetric energy density in comparison with other electrochemical systems [1]. However, there are some issues that can effectively hinder their development. They are related to such properties of the cell like reversible capacity, cycle life or power density. To increase specific capacity of the econdary lithium cell, one can use lithium as an ultimate negative electrode material. The problem with lithium consists in so-called dendritic growth of lithium.
   This problem appearing during operation of the battery limits the number of cycles that battery can deliver during its lifetime because of low Faradaic efficiency of lithium deposition–dissolution process. Much more important is that it can be also dangerous, because lithium dendrites growing inside the cell can create a short circuit between negative and positive electrode causing cell failure and possibly thermal runaway. For many years dendritic growth problem was passed round, by exchange of lithium metal with other materials that served as a host for lithium ions like different types of carbon, low potential transition metal oxides or lithium alloys. Nevertheless, these materials have low gravimetric and volumetric specific capacity (in comparison with lithium metal). Other attempts consisted in exchange of liquid electrolyte, by dry solid polymer electrolyte, but this idea is limited to temperatures slightly lower than water boiling point because of their low conductivity at ambient temperatures. Nevertheless, the problem of dendritic growth of lithium has not been solved yet and a practical use of secondary lithium metal cells depends on the solution of this problem [2,3].
   The success of practical application of a new technology to the industry depends not only on the advantages of implemented battery, but also on its manufacturing similarity with batteries that are already on the market. State of the art lithium battery technology is PLiON® [3]. The idea of this technology relays on so-called hybrid polymer electrolyte. The advantages of this technology are for example simple and cheap production and easy storage of both electrodes and electrolytes. Moreover, cells can be produced in a variety of shapes and forms. Nevertheless, up to now this technology can not be used with metallic lithium, due to the degradation of PVdF-HFP poly(vinylidene fluoride-co-hexafluoropropylene) polymer in contact with lithium metal and creation of porous lithium (lithium moss), unusable in lithium batteries [4,5]. Solution of the latter problem can be related to the lithium transference number. Elimination of these problems would play a meaningful role in the development of secondary lithium metal battery [6,7]. By adding some chemicals to solid electrolytes, lithium transference number [8–12] can be increased. Similar additive can be applied in liquid and gel electrolytes. Generally the motivation for this work was the exploration of possibilities of using inorganic additives as a means of enhancing the properties of gel electrolytes that are lower cost than boro-organic structures [13]. The latter are soluble in the electrolyte.
   Another approach consists of the application of hybrid inorganic–organic structures that are widely studied in many different areas of science, including battery electrolytes [14]. One of the driving forces to use this kind of materials is to take advantage of Lewis acid–base interactions between acidic aluminum and basic
anion centers [15–19].
   In this project we tested one soluble (AlBr3) and several insoluble ones (Al2O3 modified to a different extent with H2SO4).


   电子产品的不断发展使原来笨重且固定的系统可以被制造成简单便携式的。这产生了一个需求，即能量来源与设备兼容性的需求。目前，这样的一个来源就是锂离子电池，同其他的电化学系统相比，它具有高体积和质量能量密度的优势[1]。然而，存在的一些问题，即相关的电池的性质，例如可逆容量，循环寿命或功率密度，严重地制约着锂离子电池的发展。为了增加二次锂电池的比容量，考虑使用金属锂作为最终的负极材料。然而，锂存在的所谓的枝晶生长问题（制约了金属锂的应用）。
   电池使用中出现的沉积—溶解过程中锂的电流感应效率低的问题限制了电池使用寿命中的循环次数。更为重要的是，电池中锂的枝晶生长在正负极间建立了一个回路，可能导致电池的失效和热量的散失而引起危险。多年间，通过使用其他可以作为锂离子基体的材料，像不同类型的炭、低电位过渡金属氧化物或锂合金，代替金属锂以解决金属锂的枝晶生长。然而，同金属锂相比，这些材料的重量和体积比容量较低。其他的尝试包括使用液体电解质，干燥固体聚合物电解质替代，但是由于它们室温的电导率较低，这种方法限制在稍低于水的沸点的温度内。然而，锂的枝晶生长问题仍未解决并且二次锂金属电池的实际使用依赖于这个问题的解决方案[2,3]。
   一项新技术成功应用到这个行业不仅在于实现电池的优点，也依赖于其制造与已经在市场上的电池具有相似性。目前，最先进的锂电池技术是塑料锂离子电池，这种技术基于所谓的杂化聚合物电解质，这种技术的优点是制造简单便宜，电极和电解质易于存储，此外，电池可以制造成各种形状和状态。然而，由于偏二氟乙烯-六氟丙烯聚合物在与金属锂的接触过程中会退化和产生不能在锂电池中使用的多孔锂（锂苔），因此这种技术仍不能与金属锂使用[4,5]，后一个问题的解决与锂的迁移数目相关。这些问题的消除对二次锂电池的发展具有重要的意义[6,7]，通过添加某些化学品到固体电解质中，可以增加锂迁移数[8-12]。一般情况下，这样做的动机是探索使用无机添加剂作为提高凝胶电解质的特性的手段，这种方法比使用硼的有机结构费用更低[13]，后者可溶于电解液中。
   另一种方法是在不同科学领域被广泛研究的包括电池电解液在内的无机-有机杂化结构的应用，使用这种材料的一个驱动力是利用酸性铝和碱性阴离子中心[15-19]之间的路易斯酸碱相互作用的优势。
   在这项研究中，我们测试了一种可溶性（溴化铝）和几种不溶性的无机—有机结构（硫酸不同程度上改性的氧化铝）。

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