2017 Annual Meeting

(198c) Hierarchical NiCo2O4 Nanosheets on Carbon Nanofiber Films for High Energy Density and Long-Life Li-O2 Batteries

Authors

Lei Zhang - Presenter, South China University of Technology
Guoxue Liu, South China University of Technology
Suqing Wang, South China University of Technology
Liang-Xin Ding, South China University of Technology
Haihui Wang, South China University of Technology
Rechargeable lithium-oxygen (Li-O2) batteries are unmatched candidates amongst future electrochemical energy storage devices for electric vehicles due to their high theoretical energy density of 3505 Wh kg−1, which is about 10 times higher than that of conventional Li-ion batteries (360 Wh kg−1).[1, 2] Despite their superior theoretical storage capacity, constructing a cycling stable Li-O2 battery cathode is still facing materials challenges.[3, 4] This is traced to the sluggish kinetic of ORR/OER giving the large discharge/charge overpotentials and the random deposition of Li2O2 blocking the permeation path for oxygen and electrolyte, leading to low round-trip efficiency, poor rate capability, and short cycling performance.[5, 6] Thus, it is highly demanded to design and develop a light weight cathode with high catalytic ORR/OER activities for realizing the high energy density of Li-O2 batteries.

Herein, we propose a novel structure of hierarchical NiCo2O4 nanosheets on porous carbon nanofiber films (denoted as NiCo2O4@CNFs), for high energy density and long-life Li-O2 batteries. The nanostructured cathode integrates several desirable design rationales for high-performance Li-O2 batteries based on low-dimensional ultrathin nanosheets, lightweight conductive carbon networks, and a binder-free cathode. With the help of this rational design, the NiCo2O4@CNFs cathode exhibits excellent electrochemical performance including a high specific discharge capacity of 4179 mA h g−1, excellent energy density of 2110 Wh kg−1, and especially superior cycling stability retaining after 350 cycles. As these results, other metal-oxygen batteries, such as Zn-O2 batteries, Al-O2 batteries, and Na-O2 batteries, can be also used to the rational design of the hierarchical catalyst constructed low-dimensional nanostructure and the lightweight porous carbon nanofiber electrode toward oxygen cathodes.

References

[1] J. Lu, L. Li, J. B. Park, Y. K. Sun, F. Wu, K. Amine, Chem. Rev. 2014, 114, 5611.

[2] P. G. Bruce, S. A. Freunberger, L. J. Hardwick, J. M. Tarascon, Nat. Mater. 2012, 11, 19.

[3] N. Feng, P. He, H. Zhou, Adv. Energy Mater. 2016, 6, 201502303.

[4] Y. Li, X. Wang, S. Dong, X. Chen, G. Cui, Adv. Energy Mater. 2016, 6, 201600751.

[5] J. Wang, Y. Li, X. Sun, Nano Energy 2013, 2, 443.

[6] Z. Peng, S. A. Freunberger, Y. Chen, P. G. Bruce, Science 2012, 337, 563.