Hydrothermal synthesis of pure LiMn2O4 from nanostructured MnO2 precursors for aqueous hybrid supercapacitors

• Published in: Ionics Vol. 23; no. 5; pp. 1083 - 1090
• Main Authors: Zou, Huijun, Wang, Bing, Wen, Fengyu, Chen, Lianmei
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2017; Springer Nature B.V
• Subjects: Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Electrochemistry; Electrode materials; Energy Storage; Hydrothermal reactions; Nanowires; Optical and Electronic Materials; Original Paper; Precursors; Renewable and Green Energy; Supercapacitors; Voltammetry; δ-MnO; Hybrid supercapacitors; Hydrothermal synthesis; nanowires; α-MnO; nanoflowers; LiMn; O
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-016-1927-3

Pure LiMn 2 O 4 samples with high crystallinity (LMO-1# and LMO-2#) were successfully synthesized by a facile hydrothermal method using δ-MnO 2 nanoflowers and α-MnO 2 nanowires as the precursors. The as-prepared samples were analyzed by XRD, SEM, and Brunauer-Emmett-Teller (BET), and their capacitive properties were investigated by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge/discharge test. Two LiMn 2 O 4 samples showed good capacitive behavior in aqueous hybrid supercapacitors. AC//LMO-1# and AC//LMO-2# delivered the initial specific capacitance of 45.4 and 40.7 F g −1 in 1 M Li 2 SO 4 electrolyte at a current density of 200 mA g −1 in the potential range of 0∼1.5 V, respectively. After 1000 cycles, the capacitance retention was 97.6% for AC//LMO-1# and 93.7% for AC//LMO-2#. Obviously, LMO-1# from δ-MnO 2 nanoflowers exhibited higher specific capacitance and better cycling performance than LMO-2#, so LMO-1# was more suitable as the positive electrode material in hybrid supercapacitors.