Xuehuan Luo,Lidan Xing,Jenel Vatamanu,Jiawei Chen,Jiakun Chen,Mingzhu Liu,Cun Wang,Kang Xu,Weishan Li
A once overlooked source of electrolyte degradation incurred by dissolved manganese (II) species in lithium-ion batteries has been identified recently. In order to deactivate the catalytic activity of such manganese (II) ion, 1-aza-12-crown-4-ether (A12C4) with cavity size well matched manganese (II) ion is used in this work as electrolyte additive. Theoretical and experimental results show that stable complex forms between A12C4 and manganese (II) ions in the electrolyte, which does not affect the solvation of Li ions. The strong binding effect of A12C4 additive reduces the charge density of manganese (II) ion and inhibits its destruction of the PF 6 − structure in the electrolyte, leading to greatly improved thermal stability of manganese (II) ions-containing electrolyte. In addition to bulk electrolyte, A12C4 additive also shows capability in preventing Mn 2+ from degrading SEI on graphite surface. Such bulk and interphasial stability introduced by A12C4 leads to significantly improved cycling performance of LIBs.
Chen Zhao,Cheng Zheng,Qian Yao,Chenghui Zhang,Jian Yang
High-quality solid electrolyte interphases (SEI) are important to advanced sodium-ion batteries, particularly on anode materials. Their large structure strain/stress usually aggravates the rupture and dissolution of the SEI, then degrades the electrochemical performance. Here, sodium vinylsulfonate (SVS) is reported as a model to achieve the polymer incorporation into the SEI by in situ electrochemical polymerization. The sulfonate group in SVS activates the vinyl group and interacts with the other components, enabling the polymer to be a robust and flexible backbone of the SEI. This enhances the mechanical properties and reduces the SEI dissolution, improving the electrochemical performance of anode materials. Using commercial tin microparticles (µ-Sn) as an example, they exhibit a capacity of 516.3 mAh g −1 after 2000 cycles at 4 A g −1 , a record-high performance at high rates. This strategy is also successful in the cases of µ-Bi and µ-Sb. These results are obtained based on commercial microparticles without carbon coating. So, it is believed that it is a new and simple way to improve the electrochemical performance of Na-ion batteries.
危险品化学品经营许可证（带存储）