| 查看: 3271 | 回复: 12 | |||||||
| 当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖 | |||||||
yester木虫 (正式写手)
|
[交流]
Nature Communication 锂电相关的新发表文章 已有10人参与
|
||||||
|
Dendrite eraser: New electrolyte rids batteries of short-circuiting fibers Now a new electrolyte for lithium batteries that's described in Nature Communications eliminates dendrites while also enabling batteries to be highly efficient and carry a large amount of electric current. Batteries using other dendrite-limiting solutions haven't been able to maintain both high efficiencies and current densities. "Our new electrolyte helps lithium batteries be more than 99 percent efficient and enables them to carry more than ten times more electric current per area than previous technologies," said physicist Ji-Guang "Jason" Zhang of the Department of Energy's Pacific Northwest National Laboratory. "This new discovery could kick-start the development of powerful and practical next-generation rechargeable batteries such as lithium-sulfur, lithium-air and lithium-metal batteries." Battery 101 Most of the rechargeable batteries used today are lithium-ion batteries, which have two electrodes: one that's positively charged and contains lithium and another, negative one that's typically made of graphite. Electricity is generated when electrons flow through a wire that connects the two. To control the electrons, positively charged lithium atoms shuffle from one electrode to the other through another path: the electrolyte solution in which the electrodes sit. But graphite has a low energy storage capacity, limiting the amount of energy a lithium-ion battery can provide smart phones and electric vehicles. When lithium-based rechargeable batteries were first developed in the 1970s, researchers used lithium for the negative electrode, which is also known as an anode. Lithium was chosen because it has ten times more energy storage capacity than graphite. Problem was, the lithium-carrying electrolyte reacted with the lithium anode. This caused microscopic lithium dendrites to grow and led the early batteries to fail. Many have tweaked rechargeable batteries over the years in an attempt to resolve the dendrite problem. In the early 1990s, researchers switched to other materials such as graphite for the anode. More recently, scientists have also coated the anode with a protective layer, while others have created electrolyte additives. Some solutions eliminated dendrites, but also resulted in impractical batteries with little power. Other methods only slowed, but didn't stop, the fiber's growth. Concentrated secret sauce Thinking today's rechargeable lithium-ion batteries with graphite anodes could be near their peak energy capacity, PNNL is taking another look at the older designs. Zhang and his team sought to develop an electrolyte that worked well in batteries with a high-capacity lithium anode. They noted others had some success with electrolytes with high salt concentrations and decided to use large amounts of the lithium bis(fluorosulfonyl)imide salt they were considering. To make the electrolyte, they added the salt to a solvent called dimethoxyethane. The researchers built a circular test cell that was slightly smaller than a quarter. The cell used the new electrolyte and a lithium anode. Instead of growing dendrites, the anode developed a thin, relatively smooth layer of lithium nodules that didn't short-circuit the battery. After 1,000 repeated charge and discharge cycles, the test cell retained a remarkable 98.4 percent of its initial energy while carrying 4 milliAmps of electrical current per square centimeter of area. They found greater current densities resulted in slightly lower efficiencies. For example, a current density as high as 10 milliAmps per square centimeter, the test cell maintained an efficiency of more than 97 percent. And a test cell carrying just 0.2 milliAmps per square centimeter achieved a whopping 99.1 percent efficiency. Most batteries with lithium anodes operate at a current density of 1 milliAmps per square centimeter or less and fail after less than 300 cycles. Anode-free battery? The new electrolyte's remarkably high efficiency could also open the door for an anode-free battery, Zhang noted. The negative electrodes in today's batteries actually consist of thin pieces of metal such as copper that are coated in active materials such as graphite or lithium. The thin metal bases are called current collectors, as they are what keep electrons flowing to power our cell phones. Active materials have been needed to coat the electrodes because, so far, most electrolytes have been inefficient and continue to consume lithium ions during battery operation. But an electrolyte with more than 99 percent efficiency means there's potential to create a battery that only has a negative current collector, without an active material coating, on the anode side. "Not needing an anode could lower the cost and size of rechargeable batteries and would also significantly improve the safety of these batteries," Zhang said. The electrolyte needs to be refined before it's ready for mainstream use, however. Zhang and his colleagues are evaluating various additives to further enhance their electrolyte so a lithium battery using it could achieve more than 99.9 percent efficiency, a level that's needed for commercial adoption. They are also examining which cathode materials would work best in combination with their new electrolyte.[ Last edited by tianyufu on 2015-2-27 at 08:48 ] |
回复此楼» 本帖附件资源列表
-
欢迎监督和反馈：小木虫仅提供交流平台，不对该内容负责。
本内容由用户自主发布，如果其内容涉及到知识产权问题，其责任在于用户本人，如对版权有异议，请联系邮箱：xiaomuchong@tal.com - 附件 1 : 2015_Nature_High_rate_and_stable_cycling_of_lithium_metal_anode.pdf
2015-02-26 09:18:10, 3.03 M
» 收录本帖的淘帖专辑推荐
 锂电资源共享 | 新能源 | 锂离子电池 | 能源器件 |
» 猜你喜欢
关于碳量子点抗菌的研究
已经有15人回复
-
南大化学调剂
已经有11人回复
-
物理化学论文润色/翻译怎么收费?
已经有144人回复
-
硫酸钠溶液浓度与密度曲线
已经有0人回复
-
0703调剂
已经有4人回复
-
1
已经有21人回复
-
0703 调剂
已经有5人回复
-
招收
已经有0人回复
-
西南某211招27届博士
已经有30人回复
-
大连工业杰青/长江团队-生物质材料-储能电池方向招收2026级博士生
已经有0人回复
» 本主题相关价值贴推荐，对您同样有帮助:
- Nature communication 排名第四作者，对博士找工作有多少作用?
已经有10人回复
- nature communication 修回再投拒稿！
已经有33人回复
- Nature Communication上用于超级电容器的三维石墨烯
已经有181人回复
- nature communication 投稿格式是双栏还是单栏的啊
已经有15人回复
- Nature communication上的文章大家来看看是不是有点问题
已经有32人回复
- 请问Nature communication 投稿有模版可用吗？
已经有7人回复
- JACS和Nature Commun.哪个更好？
已经有53人回复
- 粗略统计了Nature Communication各学科的影响因子
已经有6人回复
- 元芳你怎么看，目前scientific reports影响因子2.6，nature communication影响因子9.5
已经有14人回复
- nature communications 送审
已经有24人回复
- 请问投nature communication的时候有无文章的排版template？
已经有3人回复
- 锂电池的两篇review(Nature and Materials Research Bulletin)
已经有286人回复
- 2008年nature 上由M.Armand和J.-M.Tarascon写的一篇关于锂电池方面的综述
已经有47人回复
 |
6楼2015-02-26 14:18:57
zxczxc0417
木虫 (正式写手)
- 应助: 2 (幼儿园)
- 金币: 1989.1
- 散金: 552
- 帖子: 925
- 在线: 544.3小时
- 虫号: 326712
- 注册: 2007-03-18
- 专业: 催化化学
4楼2015-02-26 11:53:44
yester
木虫 (正式写手)
- 应助: 1 (幼儿园)
- 金币: 8301.5
- 红花: 1
- 帖子: 535
- 在线: 122.8小时
- 虫号: 1049472
- 注册: 2010-06-29
- 性别: GG
- 专业: 有机分子功能材料化学
5楼2015-02-26 13:34:34
qq394871254
金虫 (正式写手)
院士
- ECEPI: 1
- 应助: 137 (高中生)
- 金币: 464.9
- 散金: 816
- 红花: 28
- 帖子: 990
- 在线: 472.7小时
- 虫号: 1157563
- 注册: 2010-11-28
- 专业: 电化学
7楼2015-02-26 15:12:49
40