Transition Metal Oxide-Based Nano-materials for Energy Storage Application

Abstract

With improvement of global economy, the fatigue of energy becomes inevitable in twenty-first century. It is expected that the increase of world energy requirements will be triple at the end of this century. Thus, there is an imperative need for development of renewable energy sources and storage systems. Among various energy storage systems, supercapacitors are ascertained one of the most significant storage devices. But the development of supercapacitor devices with high power and energy density are the greatest challenges for modern research. In this article, transition metal oxides such as TiO 2-V 2 O 5 , NiMn 2 O 4 etc. with porous structure are considered as high performance supercapacitors electrode. The effects of its structural, morphological and electrochemical properties have been studied extensively. A TiO 2-V 2 O 5 and NiMn 2 O 4 based electrode delivered specific capacitance of 310 and 875 F g À1 , respectively at a scan rate 2 mV s À1. This TiO 2-V 2 O 5 based asymmetric supercapacitor also exhibits excellent device performance with specific energy 20.18 W h kg À1 at specific power 5.94 kW kg À1 , and retained 88.0% specific capacitance at current density of 10 A g À1 after 5000 cycles.

Electrochemical Energy Storage Properties of Ni-Mn-Oxide Electrodes for Advance Asymmetric Supercapacitor Application

“…The charge balance theory ( Q + = Q – ) has been adopted to calculate the mass ratio of the ASC electrodes (eq ). where C refers to the specific capacitance (F g –1 ), Δ V represents the potential window (V), and m indicates the mass of the electrode material on both the positive and negative electrodes (g). , All electrochemical studies of ASC such as CV, GCD, and EIS have been carried out under ambient conditions, and the specific capacitance ( C sp ) (F g –1 ), energy density ( E cell ) (W h kg –1 ), and power density ( P cell ) (W kg –1 ) of this ASC device have been calculated using eqs – where I / m is the current density (A g –1 ), Δ t is the discharge time (s), and Δ V is the applied potential window (V). ,,, …”

“…are primarily used as pseudocapacitor electrode materials, which can deliver high energy density. , Among them, RuO 2 and IrO 2 have already been well established due to their excellent supercapacitive behavior, but toxicity and high cost limit their commercial application. Numerous efforts have already been made to improve the supercapacitor performance, but the low energy density and low operating voltage still pose great challenges for researchers. ,− …”

Application of Ionic Liquids for Batteries and Supercapacitors

“…For organic electrolytes with higher decomposition potential (such as propylene carbonate (PPC), acetonitrile (ACN), etc. ), cell voltage can reach up to 2.7 V, but unfortunately, they suffer from toxicity, inflammability and major safety issues [ 14 , 128 ]. Thus, in developing safe and wide potential electrolytes, compared to aqueous and organic electrolytes, ionic liquids (ILs) have gained a lot of widespread interest in recent years as SCs electrolytes, owing to their many merits such as discrete anion–cation combination, negligible volatility, non-flammability, wide potential window (up to 4.5 V) and with a high ionic conductivity [ 23 , 32 , 33 ].…”

“…and their composites (NiO-CNT, V 2 O 5 -PANI, PANI-CNT, NiMn 2 O 4 -Graphene, etc.) are usually used as pseudocapacitive electrode materials [ 2 , 14 , 15 , 16 , 17 ]. Pseudocapacitor electrodes can store energy via reversible faradic redox reactions or ion intercalation into layered structures of electrodes at the electrode/electrolyte interface, and they can reach high specific capacitance and energy density compared to EDLCs [ 18 , 19 , 20 ].…”

Untitled

“…I -V profiles from the CV were used to calculate the values of energy (E) and power (P). The calculation can be seen in (1) and(2) as stated in [12].…”