Rational Design of Statically and Dynamically Stable Lithium-Sulfur Batteries with High Sulfur Loading and Low Electrolyte/Sulfur Ratio
Rational Design of Statically and Dynamically Stable Lithium-Sulfur Batteries with High Sulfur Loading and Low Electrolyte/Sulfur Ratio
复制标题
DOI：
10.1002/adma.201705951
复制
发表时间：
2018-02-08
影响因子：
29.4
通讯作者：
Manthiram, Arumugam
中科院分区：
文献类型：
--
作者：
Chung, Sheng-Heng;Manthiram, Arumugam
锂硫电池研究的主要挑战是设计硫阴极，其表现出高的电化学效率和稳定性，同时保持硫含量和负载高以及电解质/硫比低。通过系统的研究，本文提出了一种新型的石墨烯/棉碳阴极，其能够使硫负载量和含量高达46 mg cm（-2）和70 wt%，电解质/硫比低至仅5。石墨烯/棉碳阴极在C/10和C/5速率下分别提供926和765 mA h g（-1）的峰值容量，其转化为分别为43和35 mA h cm（-2）、648和536 mA h g（-1）以及1067和881 mA h cm（-3）的高面积、重量和体积容量，具有稳定的循环能力。它们还表现出优异的上级电池储存能力，具有95%的容量保持率，每天仅为0.0012的低自放电常数，以及在长期储存六个月后稳定的储存后循环能力。这项工作展示了一种可行的方法来开发锂硫电池，其实际能量密度超过锂离子电池。
The primary challenge with lithium-sulfur battery research is the design of sulfur cathodes that exhibit high electrochemical efficiency and stability while keeping the sulfur content and loading high and the electrolyte/sulfur ratio low. With a systematic investigation, a novel graphene/cotton-carbon cathode is presented here that enables sulfur loading and content as high as 46 mg cm(-2) and 70 wt% with an electrolyte/sulfur ratio of as low as only 5. The graphene/cotton-carbon cathodes deliver peak capacities of 926 and 765 mA h g(-1), respectively, at C/10 and C/5 rates, which translate into high areal, gravimetric, and volumetric capacities of, respectively, 43 and 35 mA h cm(-2), 648 and 536 mA h g(-1), and 1067 and 881 mA h cm(-3) with a stable cyclability. They also exhibit superior cell-storage capability with 95% capacity-retention, a low self-discharge constant of just 0.0012 per day, and stable poststorage cyclability after storing over a long period of six months. This work demonstrates a viable approach to develop lithium-sulfur batteries with practical energy densities exceeding that of lithium-ion batteries.