Mesoporous ZnCo2O4 nanoflakes with bifunctional electrocatalytic activities toward efficiencies of rechargeable lithium–oxygen batteries in aprotic media

Abstract

This study reports the successful synthesis of ternary spinel-based ZnCo2O4 nanoflakes (NFs) with mesoporous architectures via the combination of a urea-assisted hydrothermal reaction with calcination in an air atmosphere. Owing to their favorable mesostructures and desirable bifunctional oxygen reduction and evolution activities, the resulting mesoporous ZnCo2O4 NFs yielded stable cyclability at a cut-off capacity of 500 mA h gcarbon(-1) in the case of aprotic Li-O2 batteries.

Compatible interface design of CoO-based Li-O2 battery cathodes with long-cycling stability

“…Co 3 O 4 was reported as a promoter to enhance the interfacial transport of LiO 2 , which imply that the favorable interaction between LiO 2 and Co-based oxides may protect carbon materials from oxidative decomposition during charge process20. Although substantial recent studies on cobalt-based oxide materials have exhibited better cycle performance, most of them attribute the improved cycle performance to the conventional electrocatalytic activity and the nanostructure of cathodes92122232425. Up to date, there is still rare report concerning the adsorption configuration of Co-based oxides with LiO 2 as a factor for enhancing the cycle performance26.…”

In Situ‐Grown ZnCo2O4 on Single‐Walled Carbon Nanotubes as Air Electrode Materials for Rechargeable Lithium–Oxygen Batteries

“…The ZCO + SWCNT mixture was not tested under this capacity-limited protocol because it had ap oorer cycling performance than the ZCO/SWCNT composite in the full discharge/charge protocol. The ZCO/ SWCNT composite electrodes reported herein demonstrate superior electrochemical performances to reported air electrodes made with ZCO nanoflakes, [32] NiCo 2 O 4 ,a nd MnCo 2 O 4 , [25][26][27][28][29] as shown in Ta ble S1 in the Supporting Information. At the same time, the ZCO/SWCNTc omposite electrode retains almost the same discharge/charge voltage profilesf or 50 cycles and leads to quite stable cycling performance at ac onstant capacity of 800 mAh g À1 within the cutoff voltages.…”

“…Many catalysts have been developed forL i-O 2 batteries, such as carbon nanotubes, nanofibers, or carbides; [3,[10][11][12][13] graphene; [14,15] metal oxides; [16][17][18] noble metals; [19][20][21][22] and perovskites. [32] However,t hey ex situ mixed the preprepared ZCO catalyst with Super Pc onductive carbon( referred to as ZCO + SP) and poly(vinylidene fluoride) (PVDF) bindert om ake air electrodes, which did not allow the ZCO nanoflakes to function well as ac atalyst;t hererfore, only very limitedc apacity (500 mAh g À1 )a nd limited cycle life (30 cycles) were obtained. [25][26][27][28][29][30][31] Hung et al also reported the use of ZnCo 2 O 4 (ZCO) as ab ifunctional catalystf or Li-O 2 batteries.…”

“…[23,24] Recently,t he electrochemicalc atalytic effects of ternary metal oxide spinel materials, for example, CoMn 2 O 4 ,M nCo 2 O 4 ,a nd NiCo 2 O 4 on the oxygen reduction reaction (ORR) and the oxygen evolution re-action (OER) have been investigated. [32] Herein, we synthesized the ZCO catalyst in situ on the surface of single-walledc arbon nanotubes (SWCNTs) to form novel catalyst/carbon composites (referred to as ZCO/SWCNTs) through af acile approach. [32] However,t hey ex situ mixed the preprepared ZCO catalyst with Super Pc onductive carbon( referred to as ZCO + SP) and poly(vinylidene fluoride) (PVDF) bindert om ake air electrodes, which did not allow the ZCO nanoflakes to function well as ac atalyst;t hererfore, only very limitedc apacity (500 mAh g À1 )a nd limited cycle life (30 cycles) were obtained.…”

Urea-assisted solvothermal synthesis of monodisperse multiporous hierarchical micro/nanostructured ZnCo2O4 microspheres and their lithium storage properties

“…In the O1s spectrum, as shown in Fig. 4d, two peaks 529.7 and 531.3 eV corresponded to the oxygen species of the Co-O and Zn-O bands in ZnCo 2 O 4 [30]. The specific surface area and porous nature of multiporous ZnCo 2 O 4 microspheres are further characterized by Brunauer-Emmett-Teller (BET) analysis using N 2 adsorption-desorption isotherm, as shown in Fig.…”