Graphene-oxide-wrapped ZnMn 2 O 4 as a high performance lithium-ion battery anode

• Published in: Nanotechnology 2017-11, Vol.28 (45), p.455401
• Main Authors: Sun, Qian, Bijelić, Mirjana, Djurišić, Aleksandra B, Suchomski, Christian, Liu, Xiang, Xie, Maohai, Ng, Alan M C, Kong Li, Hang, Shih, Kaimin, Burazer, Sanja, Skoko, Željko, Djerdj, Igor, Popović, Jasminka
• Format: Article
• Language: English
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/1361-6528/aa8a5b

Cation distribution between tetrahedral and octahedral sites within the ZnMn O spinel lattice, along with microstructural features, is affected greatly by the temperature of heat treatment. Inversion parameters can easily be tuned, from 5%-19%, depending on the annealing temperature. The upper limit of inversion is found for T = 400 °C as confirmed by x-ray powder diffraction and Raman spectroscopy. Excellent battery behavior is found for samples annealed at lower temperatures; after 500 cycles the specific capacity for as-prepared ZnMn O is 909 mAh g , while ZnMn O heat-treated at 300 °C is 1179 mAh g , which amounts to 101% of its initial capacity. Despite the excellent performance of a sample processed at 300 °C at lower charge/discharge rates (100 mAh g ), a drop in the specific capacity is observed with rate increase. This issue is solved by graphene-oxide wrapping: the specific capacity obtained after the 400th cycle for graphene-oxide-wrapped ZnMn O heat-treated at 300 °C is 799 mAh g at a charge/discharge rate 0.5 A g , which is higher by a factor of 6 compared to samples without graphene -oxide wrapping.