排序方式: 共有2条查询结果,搜索用时 0 毫秒
1
1.
Cation–anion interaction with different ratios of salt to solvent is investigated by FT-Raman spectroscopy. The fitting result of the C–N–C bending vibration manifests that the cation–anion coordination structure changes tremendously with the variation of salt concentration. It is well known that lithium-ion transport in ultrahigh salt concentration electrolyte is dramatically different from that in dilute electrolyte, due to high viscosity and strong cation–anion interaction. In ultrahigh salt concentrated "solvent-in-salt" electrolyte(SIS-7#), we found, on one hand, that the cation and anion in the solution mainly formed cation–anion pairs with a high Li~+coordination number(≥ 1), including intimate ion pairs(20.1%) and aggregated ion pairs(79.9%), which not only cause low total ionic conductivity but also cause a high lithium transference number(0.73). A possible lithium transport mechanism is proposed: in solvent-in-salt electrolytes, lithium ions' direct movement presumably depends on Li-ion exchange between aggregated ion pairs and solvent molecules, which repeats a dissolving and re-complexing process between different oxygen groups of solvent molecules. 相似文献
2.
Concentrated dual-salt electrolytes for improving the cycling stability of lithium metal anodes 下载免费PDF全文
Lithium(Li) metal is an ideal anode material for rechargeable Li batteries, due to its high theoretical specific capacity(3860 mAh/g), low density(0.534 g/cm~3), and low negative electrochemical potential(-3.040 V vs. standard hydrogen electrode). In this work, the concentrated electrolytes with dual salts, composed of Li[N(SO_2F)_2](Li FSI) and Li[N(SO_2CF_3)_2](Li TFSI) were studied. In this dual-salt system, the capacity retention can even be maintained at 95.7%after 100 cycles in Li|Li FePO_4 cells. A Li|Li cell can be cycled at 0.5 mA/cm~2 for more than 600 h, and a Li|Cu cell can be cycled at 0.5 m A/cm~2 for more than 200 cycles with a high average Coulombi efficiency of 99%. These results show that the concentrated dual-salt electrolytes exhibit superior electrochemical performance and would be a promising candidate for application in rechargeable Li batteries. 相似文献
1