TY - JOUR
T1 - Ionic liquid-reinforced carbon nanofiber matrix enabled lean-electrolyte Li-S batteries via electrostatic attraction
AU - Wang, Xinyang
AU - Zhang, Weidong
AU - Wang, Duo
AU - Zhuang, Houlong L.
AU - Li, Siyuan
AU - Fan, Lei
AU - LinlinLi,
AU - Wang, Xiao
AU - He, Yi
AU - Lu, Yingying
N1 - Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2020/4
Y1 - 2020/4
N2 - Lithium–sulfur (Li–S) batteries are one of the most promising battery technologies to support the fast-expanding electrical vehicle and large-scale energy storage market. Reducing the electrolyte amount is critical for the high specific energy of Li–S batteries in practice. However, using lean electrolytes (that is, with a low Electrolyte to Sulfur (E/S) ratio) always leads to a sluggish sulfur reaction kinetics. Herein, a design strategy based on electrostatic attractions between the cations of ionic liquids and the polysulfide anions is proposed to boost the reaction. The positively charged ionic liquid grafted carbon nanofibers can offer a non-contact coulomb force to attract the polysulfides, accelerate the transport of S species for further strong adsorption and therefore improve the reactant kinetics, especially in a lean electrolyte condition. The electrostatic properties are verified by Zeta potential analysis, Kelvin probe force microscopy test and DFT calculation. As a result, it maintains a high stable discharge capacity of 830 mAh g−1 after 400 cycles (sulfur mass loading: 4.0 mg cm−2; electrolyte/sulfur ratio = 5 μl mg−1) and a capacity up to 845 mAh g−1 with an extremely challenging E/S ratio of 3.5 μl mg−1. This work provides a rational guidance for electrostatic design and a new strategy for the development of lean-electrolyte Li-S batteries.
AB - Lithium–sulfur (Li–S) batteries are one of the most promising battery technologies to support the fast-expanding electrical vehicle and large-scale energy storage market. Reducing the electrolyte amount is critical for the high specific energy of Li–S batteries in practice. However, using lean electrolytes (that is, with a low Electrolyte to Sulfur (E/S) ratio) always leads to a sluggish sulfur reaction kinetics. Herein, a design strategy based on electrostatic attractions between the cations of ionic liquids and the polysulfide anions is proposed to boost the reaction. The positively charged ionic liquid grafted carbon nanofibers can offer a non-contact coulomb force to attract the polysulfides, accelerate the transport of S species for further strong adsorption and therefore improve the reactant kinetics, especially in a lean electrolyte condition. The electrostatic properties are verified by Zeta potential analysis, Kelvin probe force microscopy test and DFT calculation. As a result, it maintains a high stable discharge capacity of 830 mAh g−1 after 400 cycles (sulfur mass loading: 4.0 mg cm−2; electrolyte/sulfur ratio = 5 μl mg−1) and a capacity up to 845 mAh g−1 with an extremely challenging E/S ratio of 3.5 μl mg−1. This work provides a rational guidance for electrostatic design and a new strategy for the development of lean-electrolyte Li-S batteries.
KW - Carbon nanofibers
KW - Electrostatic effects
KW - Ionic liquids
KW - Lean electrolyte conditions
KW - Lithium-sulfur batteries
UR - http://www.scopus.com/inward/record.url?scp=85075435780&partnerID=8YFLogxK
U2 - 10.1016/j.ensm.2019.11.008
DO - 10.1016/j.ensm.2019.11.008
M3 - Article
AN - SCOPUS:85075435780
SN - 2405-8297
VL - 26
SP - 378
EP - 384
JO - Energy Storage Materials
JF - Energy Storage Materials
ER -
