Electrochemical Properties of Nanocrystalline Li4Mn5O12 for Hybrid Capacitor

Thursday, 28 May 2015: 08:20
Continental Room B (Hilton Chicago)
T. V. Man (Department of Physical Chemistry, VNUHCM-Univ. Science), N. L. T. Huynh (APCLAB, VNUHCM-University of Science), T. V. Le (Faculty of Materials Technology), and L. M. L. Phung (APCLAB, VNUHCM-Univ. Science)
The hybrid capacitor or asymmetric capacitor is the hybridization of electrochemical capacitor and rechargeable batteries. The device is developed by hybridization on the electrode level; therefore, it is based on a battery anode (charged by faradic reaction) and electrochemical capacitor electrode (charge stored in the electrochemical double layer) [1]. Sometimes, the name “lithium-ion” capacitor was introduce to described a device using a graphite negative electrode and activated carbon (AC) based positive electrode in combination with a Li+ containing electrolyte [2].

In such device, different types of materials have been proposed for faradic component. Lithium insertion compounds used in lithium-ion batteries have attracted a lot of interest due to high specific charge. They have been typically used in organic electrolyte but the aqueous solutions are not missing [3,4]. In this work, nanocrystalline Li4Mn5O12 was low-temperature synthesized by sol-gel method with citric acid as a chelating agent. Various initial synthesis conditions were studied such as: pH of solution, the ratio of citric acid to total metal ions, the precursor of lithium salts. The structure, morphology and electrochemical properties of materials are characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), transmission electronic microscopy (TEM), cyclic voltammetry (CV) and galvanostatic cycling with potential limit (GCPL). The stoichiometric of formula was exactly determined by reduction-oxidation titration and flame atomic absorption spectrophotoscopy (FAAS).

The resulting materials exhibited the particles size of 50 – 100 nm. The electrochemical results showed that Li4Mn5O12 synthesized at pH = 9 and the ratio of citric acid to total metal ions 1:1 exhibited the best electrochemical capacitive performance within potential range of  0 – 1.4 V in 1M Li2SO4. A maximum specific capacitance of 20 F.g-1 during 200 cycles was obtained for hybrid capacitor for AC/Li4Mn5O12 at high discharge rate of 5 A.g-1.


The authors would like to thank Office of Naval Research Global (ONRG) for the grant N62909-13-1-N235. The authors acknowledge funding from VNU-HCM under the grants HS2013-76-01.



 [1]. D. Cericola, Electrochimica Acta 72 (2010) A536.

[2]. O. Hatozaki,  Proc. Advanced Capacitor World Summit 2008,  San Diego, CA, USA, 2008.

[3]. Y.J. Hao,Y.Y. Wang, Q.Y. Lai, Z. Zhao, L.M. Chen, X.Y. Ji, Journal of Solid State Electrochemistry, 13 (2009) 905. 

[4]. K. Naoi, S. Ishimoto,Y. Isobe, S. Aoyagi, Journal of Power Sources 195 (2010) 6250.