Design of Perovskite Oxides as Anion-Intercalation-Type Electrodes for Supercapacitors: Cation Leaching Effect

Abstract

Oxygen ions can be exploited as a charge carrier to effectively realize a new type of anion-intercalation supercapacitor. In this study, to get some useful guidelines for future materials development, we comparatively studied SrCoO3-δ (SC), Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF), and Co3O4 as electrodes in supercapacitors with aqueous alkaline electrolyte. The effect of interaction between the electrode materials with the alkaline solution was focused on the structure and specific surface area of the electrode material, and ultimately the electrochemical performance was emphasized. Both BSCF and SC were found to experience cation leaching in alkaline solution, resulting in an increase in the specific surface area of the material, but overleaching caused the damage of perovskite structure of BSCF. Barium leaching was more serious than strontium, and the cation leaching was component dependent. Although high initial capacitance was achieved for BSCF, it was not a good candidate as intercalation-type electrode for supercapacitor because of poor cycling stability from serious Ba(2+) and Sr(2+) leaching. Instead, SC was a favorable electrode candidate for practical use in supercapacitors due to its high capacity and proper cation leaching capacity, which brought beneficial effect on cycling stability. It is suggested that cation leaching effect should be seriously considered in the development of new perovskite materials as electrodes for supercapacitors.

Fabrication of a Mo‐Doped Strontium Cobaltite Perovskite Hybrid Supercapacitor Cell with High Energy Density and Excellent Cycling Life

“…SCM voltammograms exhibit very high capacitance in KOH (690.4 Fg À1 )c ompared with KNO 3 (67.35 Fg À1 )a t5mV s À1 indicating that OH À ions are highly favorable for intercalationtype energy storage.T he cyclic voltammograms at different scan rates (Figure 4a)d isplay two redoxp eaks, confirming the pseudocapacitive behavior of SCM.T he charging and discharging characteristics shown in Figure 4b are noticeably deviated from isosceles triangular form andt hus exhibit pseudocapacitance. [36] SCM shows better performance than SC (low capacitance 623 Fg À1 at 5Ag À1 and 417 Fg À1 at 10 Ag À1 ,F igure S8), which is attributed to highero xygen vacancies and structural stability. The charge transfer resistance( R ct )w as calculated as 0.251 W by using the Nyquist plot fitting of Randle's circuit ( Figure S9).…”

“…[36] Herein, the power law is used to determine the charge storage process. [36] Herein, the power law is used to determine the charge storage process.…”

“…[24] Considering the recent research on doped strontium cobaltite for charge storagei nt he arena of energy storage devicesa nd the significance of hybrid cells, the undertaken work is focused on hybrid supercapacitor: SCM k LRGONR assembled by using SCM as the cathode andl acey reducedg raphene oxide nanoribbon (LRGONR) as the anode material. [24] In contrast, all the diffraction peaks of SC matched with the hexagonal phase ( Figure S1 ai nt he Supporting Information) [36] of strontium cobaltite. It differs from other nanoparticle synthesis methodologies in terms of delivering high purity metal oxidesw ith enhanced electricalc onductivity owing to improved interfacial contactsb etween grains.…”

Facile Synthesis and Electrochemical Properties of Perovskite‐type CeMnO3 Nanofibers

“…Owing to the serious energy crisis, it is an extraordinary emergency to develop an environmentally friendly, sustainable, and effective energy generation, storage and conversion system. Supercapacitors are considered as a significant kind of energy storage and conversion devices on account of their eco‐friendliness, fast charging/discharging rate, long retention, high power and energy density, and wide working temperature . Depending on the energy storage mechanism, supercapacitors can commonly sort into electrochemical double layer capacitors (EDLCs), in which carbon materials are mainly applied, and pseudocapacitors, in which transition metal oxides and conductive polymers are widely utilized .…”

A Ceramic‐Based Separator for High‐Temperature Supercapacitors

“…Supercapacitors (SCs) have drawn extensive attention owing to their high power density and long cycle life . What is more, high‐temperature supercapacitors (HTSCs) that could satisfy some special requirements in drilling, space, and military applications are also very desirable.…”