Augmenting the nickel-cobalt layered double hydroxide performance: Virtue of doping. (October 2020)

• Record Type: Journal Article
• Authors: Nanwani, Alisha; Deshmukh, Kavita A.; Subramaniyam, Chandrasekar M; Deshmukh, Abhay D.
• Is Part Of: Journal of energy storage. Volume 31(2020)
• Publication Date: 2020-10
• Subjects: Doping effect -- Asymmetric supercapacitor -- Layered double hydroxides (LDHs) -- Energy density -- Energy storage -- Ni-Co LDH; Energy storage -- Periodicals; Energy storage -- Research -- Periodicals; 621.3126
• DOI: 10.1016/j.est.2020.101604
• Languages: English
• ISSNs: 2352-152X

Abstract

Highlights: Proposed the doping effect of s-block (magnesium) element on the electrochemical properties and structural integrity of nickel-cobalt-hydroxide as electrode material for supercapacitors. Mg 2+ being a Lewis acid provides the excess oxidation states in the Ni-based materials and Mg sites with oxidation states proves to be active sites. Different stoichiometric ratios of magnesium and nickel are studied amongst which Ni0.5 Mg0.5 -LDHs reveals the highest capacitance of specific capacity of 624 Cg −1 at the current density of 10 Ag -1 . The method used to prepare Mg-doped nickel cobalt layered hydroxide is electrodeposition which is industrially viable so assures reproducibility. Abstract: Doping is the most effective strategy to improve the electrochemical performance of supercapacitors. Herein, we report the doping effect of Magnesium on structural instability of Ni-Co LDHs as the supercapacitor electrode material. The morphology of different compositions of magnesium are studied. The derived material with the Ni:Mg ratio of 1:1 displayed an excellent specific capacity of 624 Cg −1 at current density of 10 Ag −1 . Moreover, the specific capacity remained at 80% after 3000 cycles which suggest excellent cycle stability. An asymmetrc device was fabricated with N/M2 as positive electrode and activated carbon cloth as negative electrode, which displayed a specific capacitance of 200 Fg −1 at 0.25 Ag −1 with the energy density of 28 Whkg −1 . The device showed the capacitance retention of about 99% after 1000 cycles at 1 Ag −1 . Therefore, improved structural integrity, makes this material a suitable candidate for supercapacitors.