Long term stability of Li-S batteries using high concentration lithium nitrate electrolytes
Long term stability of Li-S batteries using high concentration lithium nitrate electrolytes
复制标题
DOI：
10.1016/j.nanoen.2017.09.015
复制
发表时间：
2017-10-01
期刊：
影响因子：
17.6
通讯作者：
Zhang, Ji-Guang
中科院分区：
文献类型：
--
作者：
Adams, Brian D.;Carino, Emily V.;Zhang, Ji-Guang
锂硫（Li-S）电池因其极高的理论比能量（2500 W·h·kg(-1)）而成为电动汽车和电网储能应用所需的下一代储能系统的非常有前途的候选者。然而，重复锂金属电镀/剥离过程中库仑效率（CE）较低，严重限制了可充电锂硫电池的实际应用。在这项工作中，开发了一种基于二甘醇二甲醚（G2）溶剂中高浓度LiNO3的新型电解质体系，该体系能够实现Li金属电镀/剥离的极高CE，从而使Li阳极在含硫电解质中具有高稳定性。事实证明，定制锂阳极电解质特性是提高锂硫电池容量保持率和循环寿命的非常成功的策略。该电解液在 200 多个锂电镀/剥离循环中提供大于 99% 的 CE。相比之下，在相同条件下，在最先进的 1 M LiTFSI + 0.3 M LiNO3 的 1,3-二氧戊环：1,2-二甲氧基乙烷 (DOL:DME) 电解质中，Li 阳极的循环次数少于 35 次（具有高 CE）。新型电解质实现的稳定锂负极可能会加速高能量密度锂硫电池在电动汽车和大规模电网储能市场的应用。
The lithium-sulfur (Li-S) battery is a very promising candidate for the next generation of energy storage systems required for electrical vehicles and grid energy storage applications due to its very high theoretical specific energy (2500 W h kg(-1)). However, low Coulombic efficiency (CE) during repeated Li metal plating/stripping has severely limited the practical application of rechargeable Li-S batteries. In this work, a new electrolyte system based on a high concentration of LiNO3 in diglyme (G2) solvent is developed which enables an exceptionally high CE for Li metal plating/stripping and thus high stability of the Li anode in the sulfur-containing electrolyte. The tailoring of electrolyte properties for the Li anode has proven to be a highly successful strategy for improving the capacity retention and cycle life of Li-S batteries. This electrolyte provides a CE of greater than 99% for over 200 cycles of Li plating/stripping. In contrast, the Li anode cycles for less than 35 cycles (with a high CE) in the state-of-the-art 1 M LiTFSI + 0.3 M LiNO3 in 1,3-dioxolane: 1,2-dimethoxyethane (DOL:DME) electrolyte under the same conditions. The stable Li anode enabled by the new electrolyte may accelerate the applications of high energy density Li-S batteries in both electrical vehicles and large-scale grid energy storage markets.