Emerging Materials for Sodium-Ion Hybrid Capacitors: A Brief Review

Abstract

The demand for energy storage is exponentially increasing with growth of the human population, which is highly energy intensive. Batteries, supercapacitors, and hybrid capacitors are key energy storage technologies, and lithium and sodium ions are critical influencers in redefining the performances of such devices. Batteries can store energy with high density, and capacitors can deliver a high power density. In addition, hybrid capacitors bridge the energy and power gap between a battery and supercapacitor by combining reactions from a battery-type electrode and a capacitor-type electrode. Sodium-ion hybrid capacitors (NICs) can combine the benefits of high power capacitors and high energy batteries at a cost potentially lower than that of Li analogues. However, research on NICs is in the nascent stage and requires significant attention to enable their use in practical applications. This review presents a comprehensive summary of the development of Na-ion hybrid capacitors based on carbon materials, a sodium superionic conductor NASICON, and metal oxide or sulfide-type anodes, with a particular emphasis on the performance metrics. Furthermore, design strategies and unsolved issues in emerging capacitor systems, such as pseudocapacitive electrodes, organic electrodes, MXenes, and flexible capacitors, which could be trend setters for next-generation applications, are the focus. The revolving issues with each system and the strategies to overcome such issues are also briefly discussed. A perspective and outlook on the future of NICs will help the scientific community direct their future studies.

Engineering of Transition Metal Sulfide Nanostructures as Efficient Electrodes for High-Performance Supercapacitors

“…The standard SC was invented by Robert Rightmire, and credit for fabrication of the first commercial SCs in 1975 went to the Japanese company Nippon Electric Company. The electrode materials, electrolytes, and operation conditions are the main factors that determine the SC’s performance. ,− Transition metal-based electrode materials (TMEMs) are among the most promising electrodes for SCs, due to their relative stability, specific power, and quick charging/discharging rates. , Various transition metal-based oxides (TMOs), sulfides (TMSs), and phosphides (TMPs) have been developed for SCs. − However, the low energy density, strong internal resistance, and low mechanical strength of TMEMs remain critical barriers precluding their utilization in practical SCs . The morphology and composition of TMEMs and the type of the electrolytes are the main factors that determine the SC’s performance .…”

Zinc‐ion hybrid supercapacitors: Design strategies, challenges, and perspectives

“…Instead, hybrid supercapacitors (HSCs), which are composed of battery-type electrodes with rich redox reactions and capacitor-type electrodes with fast ionic conductivity, may provide a good solution, because HSCs would combine the benefits of batteries and capacitors to meet the requirements of energy storage systems that require both a high energy density and a high power density. [17][18][19][20][21] The HSCs are classified as alkali metal ion (Li + /Na + / K + ) HSCs [22][23][24][25] or multivalent metal ion (Zn 2+ /Mg 2+ /Ca 2+ / Al 3+ ) [26][27][28] HSCs, based on the different metal ion types. In recent years, extensive investigations on these HSCs have been performed and most were related to lithium-ion HSCs, although a number of issues still existed for lithiumion HSCs in practice.…”

“…Instead, hybrid supercapacitors (HSCs), which are composed of battery‐type electrodes with rich redox reactions and capacitor‐type electrodes with fast ionic conductivity, may provide a good solution, because HSCs would combine the benefits of batteries and capacitors to meet the requirements of energy storage systems that require both a high energy density and a high power density. [ 17–21 ]…”

Improved Electrochemical Performance from Nano-Cobalt Oxide: Bifunctional Application in Energy Generation and Storage

“…18,19 By and large, prosperous activity of nanomaterials observed in all possible fields is an important topic of today's era in which any old or new material cannot be deliberately overlooked without investigation for any applications. 20 However, the global demand for "energy" either "in storing" (in terms of capacitors and supercapacitors) or "in producing" (in terms of water splitting) is still a great challenge from a material point of view that needs some attention to look over some missing parameters that may account for their better results. Moreover, materials that can exhibit both the properties of energy generation and storage will certainly have an advantage.…”

“…This also helps to get rid of the global crisis in industrial functioning, which still stands as a hindrance due to the lack of appropriate research in the midst of emerging modern technology. − As a consequence, identifying and reengineering appropriate materials that can have this multifunctional approach to energy generation and energy storage becomes important . In view of this, new advanced functional materials in their bulk, as well as the nanostructured forms, are explored to get improved application. , Recent advances in the discovery of 2D materials, metal/covalent organic frameworks, carbide–nitride nanosheets, and carbon-based nanocomposites have shown promising results in the area of energy storage, , water splitting, sensing, CO 2 reduction, photocatalytic, and electrochromic , applications, which is a great interest of today’s research. , By and large, prosperous activity of nanomaterials observed in all possible fields is an important topic of today’s era in which any old or new material cannot be deliberately overlooked without investigation for any applications . However, the global demand for “energy” either “in storing” (in terms of capacitors and supercapacitors) or “in producing” (in terms of water splitting) is still a great challenge from a material point of view that needs some attention to look over some missing parameters that may account for their better results.…”