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yanbeilei_2金虫 (正式写手)
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[求助]
求助大神翻译前言，锂电方面 已有1人参与
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随着锂离子电池快速发展，插层化合物intercalation compounds的研究逐渐成为热点研究领域。其中，Ti-O化合物Li4Ti5O12具有非常良好的应用、发展潜力，因为它具有本质上的安全特性。它具有较高的嵌锂电压（ca. 1.5 V vs Li+/Li)），能够避免形成SEI膜，同时，在锂离子的嵌入脱出过程中，晶胞结构保持稳定，称为零相变材料。上述优点，使Li4Ti5O12材料作为应用在大规模储能、电动车等领域，锂电池的负极材料。但是，Li4Ti5O12材料在应用过程中仍面临着动力学问题，例如，较低的电子导电性(ca.10-13 S cm-1)和较低的锂离子扩散速率(ca.10-9 to 10-13cm2s-1)。直接限制了锂离子电池的倍率和循环性能。 目前，采用多种方法以改良Li4Ti5O12材料的倍率和循环性能，例如，掺杂外部离子、控制材料形貌、添加导电物质等。其中，尤其值得注意的是，碳涂层技术carbon-based coating technique与纳米技术相结合，缩短锂离子、电子传输距离为基础，从而增强电池材料的倍率、循环性能。然而，由于碳涂层技术与Li4Ti5O12最大的优势、本质的安全性相违背，因此研究工作的重点转向了carbon-free coatings非碳处理技术，致力于开发出高振实密度、高倍率性能的电池材料。Ti3+掺杂改性结合材料的纳米结构控制，也有很多的文献报道。但是，纳米结构在制备过程中容易造成颗粒团聚，从而造成容量和倍率的损耗，不利于实际工业化生产。还有以金属钛片为基本材质，能够获得非常高的倍率性能。包括现有的溶胶-墨水可涂装钛酸锂材料，但是都存在制备工艺复杂、制备周期长、不利于锂电池实际的工业化发展前景。因此，可以 而向Li4Ti5O12材料中，直接添加金属材料，可以直接增强材料的电导率，提高电极材料的电化学性能，同时提高材料的振实密度，但是由于实际操作问题，这方面鲜有报道。 |
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redwang8181
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yanbeilei_2: 金币+100 2017-03-13 10:05:44
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感谢参与，应助指数 +1
yanbeilei_2: 金币+100 2017-03-13 10:05:44
ANDPing: 金币+2, 辛苦了，可参与《专业外语》版置顶帖活动：http://muchong.com/bbs/viewthread.php?tid=11135508&fpage=1，获得额外奖励 2017-03-13 10:20:17
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With the rapid development of the lithium-ion batteries, the research of the intercalation compounds is becoming the attentive study area. Hereinto, the Ti-O based compounds Li4Ti5O12 has a good application future and development potential due to its inherent safety. It has a higher lithium insertion voltage (ca.1.5VVS Li+/Li) so as to avoid forming the SEI membrane. Meantime, the unit cell structure remains stable during the lithium ion insertion/extraction due to its Zero-strain characteristic. The advantages mentioned above, which enable the Li4Ti5O12 to be the potential materials which could be widely used in the application of large-scale stored energy, electric car and the anode materials of the lithium-ion batteries. However, there still exist the dynamics problems when using the Li4Ti5O12 material. For example, the lower electronic conductivity(ca.10-13 S cm-1) and the lower speed of lithium ion(ca.10-9 to 10-13cm2s-1) directly affects its rate and cycle performance. At present, many methods are used to improve the rate and cycle performance of the Li4Ti5O12 material. For example, through doping external ions, controlling the shape of the material and adding the electric conduction matters into it and so on. It’s worth noting that, carbon-based coating technique combined with nanotechnology which based on shortening the transmission distance of lithium ion and electron could enhance the rate and cycle performance of the battery materials. However, due to the carbon-based coating technique violates the inherent safety performance of the the Li4Ti5O12 material, the emphasis of the research work was shifted to the carbon-free coatings technology, which devotes to develop the battery materials with higher density and higher rate performance. Besides, there are also many literature reports about controlling the nanostructure through doping Ti3+ modified materials. However, in the process of preparation the nanostructure of the material caused to particle aggregation and resulted in the loss of the capacity and rate, which against the actual industrial production. There are also other methods including present sol-ink being able to coated as the lithium titanate materials which using the metal titanium as the substrate to try to obtain higher rate performance, all of which against the actual industrial production due to the complex preparation technology and longer preparation cycle. So there is another method that adding the metal elements in the Li4Ti5O12 material directly, which can enhance the electric conducting, the density of the material and improve the electrochemical performance of the electrode materials. However, there were few reports about the research on the technology due to the actual operation. |
2楼2017-03-06 17:40:06
yanbeilei_2
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3楼2017-03-10 22:32:43
