title: Nanostructured porous RuO2/MnO2 as a highly efficient catalyst for high-rate Li-O2 batteries.
abstract: Despite the recent advancements in Li-O(2) (or Li-air) batteries, great challenges still remain to realize high-rate, long-term cycling. In this work, a binder-free, nanostructured RuO(2)/MnO(2) catalytic cathode was designed to realize the operation of Li-O(2) batteries at high rates. At a current density as high as 3200 mA g(-1) (or ∼1.3 mA cm(-2)), the RuO(2)/MnO(2) catalyzed Li-O(2) batteries with LiI can sustain stable cycling of 170 and 800 times at limited capacities of 1000 and 500 mA h g(-1), respectively, with low charge cutoff potentials of ∼4.0 and <3.8 V, respectively. The underlying mechanism of the high catalytic performance of MnO(2)/RuO(2) was also clarified in this work. It was found that with the catalytic effect of RuO(2), Li(2)O(2) can crystallize into a thin-sheet form and realize a conformal growth on sheet-like δ-MnO(2) at a current density up to 3200 mA g(-1), constructing a sheet-on-sheet structure. This crystallization behavior of Li(2)O(2) not only defers the electrode passivation upon discharge but also renders easy decomposition of Li(2)O(2) upon charge, leading to low polarizations and reduced side reactions. This work provides a unique design of catalytic cathodes capable of controlling Li(2)O(2) growth and sheds light on the design of high-rate, long-life Li-O(2) batteries with potential applications in electric vehicles.
authors.affiliation: State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, P. R. China. xiejian1977@zju.edu.cn.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Wang
authors.forename: Liliang
authors.initials: L
authors.lastname: Huang
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: Jian
authors.initials: J
authors.lastname: Xie
authors.forename: Gaohui
authors.initials: G
authors.lastname: Du
authors.forename: Shichao
authors.initials: S
authors.lastname: Zhang
authors.forename: Peiyi
authors.initials: P
authors.lastname: Zhu
authors.forename: Gaoshao
authors.initials: G
authors.lastname: Cao
authors.forename: Xinbing
authors.initials: X
authors.lastname: Zhao