Abstract
As a step towards efficient and cost-effective electrocatalytic cathodes for Li–O 2 batteries, highly porous hausmannite-type Mn 3O 4 hollow nanocages (MOHNs) of a large diameter of ~250 nm and a high surface area of 90.65 m 2·g−1 were synthesized and their physicochemical and electrochemical properties were studied in addition to their formation mechanism. A facile approach using carbon spheres as the template and MnCl 2 as the precursor was adopted to suit the purpose. The MOHNs/Ketjenblack cathode-based Li–O 2 battery demonstrated an improved cyclability of 50 discharge–charge cycles at a specific current of 400 mA·g −1 and a specific capacity of 600 mAh·g −1. In contrast, the Ketjenblack cathode-based one can sustain only 15 cycles under the same electrolytic system comprised of 1 M LiTFSI/TEGDME. It is surmised that the unique hollow nanocage morphology of MOHNs is responsible for the high electrochemical performance. The hollow nanocages were a result of the aggregation of crystalline nanoparticles of 25–35 nm size, and the mesoscopic pores between the nanoparticles gave rise to a loosely mesoporous structure for accommodating the volume change in the MOHNs/Ketjenblack cathode during electrocatalytic reactions. The improved cyclic stability is mainly due to the faster mass transport of the O 2 through the mesoscopic pores. This work is comparable to the state-of-the-art experimentations on cathodes for Li–O 2 batteries that focus on the use of non-precious transition materials.
Original language | English |
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Article number | 308 |
Journal | Nanomaterials |
Volume | 8 |
Issue number | 5 |
DOIs | |
Publication status | Published - 1 May 2018 |
Keywords
- Cyclic stability
- Electrocatalytic cathodes
- Hollow nanocages
- Li-O batteries
- Transition metals
ASJC Scopus subject areas
- General Materials Science
- General Chemical Engineering