Quasi-solid-state Zn-air batteries are usually limited to relatively low-rate ability (<10 mA cm−2), which is caused in part by sluggish oxygen electrocatalysis and unstable electrochemical interfaces. Here we present a high-rate and robust quasi-solid-state Zn-air battery enabled by atomically dispersed cobalt sites anchored on wrinkled nitrogen doped graphene as the air cathode and a polyacrylamide organohydrogel electrolyte with its hydrogen-bond network modified by the addition of dimethyl sulfoxide. This design enables a cycling current density of 100 mA cm−2 over 50 h at 25 °C. A low-temperature cycling stability of over 300 h (at 0.5 mA cm−2) with over 90% capacity retention at −60 °C and a broad temperature adaptability (−60 to 60 °C) are also demonstrated.
Herein, we successfully construct bifunctional electrocatalysts by synthesizing atomically dispersed Fe−Se atom pairs supported on N‐doped carbon (Fe−Se/NC). The obtained Fe−Se/NC shows a noteworthy bifunctional oxygen catalytic performance with a low potential difference of 0.698 V, far superior to that of reported Fe‐based single‐atom catalysts. The theoretical calculations reveal that p‐d orbital hybridization around the Fe−Se atom pairs leads to remarkably asymmetrical polarized charge distributions. Fe−Se/NC based solid‐state rechargeable Zn‐air batteries (ZABs−Fe−Se/NC) present stable charge/discharge of 200 h (1090 cycles) at 20 mA cm−2 at 25 °C, which is 6.9 times of ZABs−Pt/C+Ir/C. At extremely low temperature of −40 °C, ZABs−Fe−Se/NC displays an ultra‐robust cycling performance of 741 h (4041 cycles) at 1 mA cm−2, which is about 11.7 times of ZABs−Pt/C+Ir/C. More importantly, ZABs−Fe−Se/NC could be operated for 133 h (725 cycles) even at 5 mA cm−2 at −40 °C.
Robust operation of Zn-air batteries (ZABs) with high capacity and excellent energy efficiency is desirable for practical harsh applications, whose bottlenecks are mainly originated from the sluggish oxygen catalytic kinetics and unstable Zn|electrolyte interface. In this work, we synthesized the edge-hosted Mn-N 4 -C 12 coordination supported on Ndoped defective carbon (Mn 1 /NDC) catalyst, exhibiting a good bifunctional performance of the oxygen reduction/evolution reaction (ORR/OER) with a low potential gap of 0.684 V. Theoretical calculation reveals that the edge-hosted Mn-N 4 -C 12 coordination displayed the lowest overpotential of the ORR/ OER owing to the decreased adsorption free energy of OH*. The Mn 1 /NDC-based aqueous ZABs deliver impressive rate performance, ultralong discharging lifespan, and excellent stability. Notably, the assembled solid-state ZABs demonstrate a high capacity of 1.29 Ah, a large critical current density of 8 mA cm −2 , and robust cycling stability with excellent energy efficiency at −40 °C, which should be attributed to the good bifunctional performance of Mn 1 /NDC and anti-freezing solidstate electrolyte (SSE). Meanwhile, the zincophilic nanocomposite SSE with high polarity accounts for the stable Zn|SSE interface compatibility. This work not only highlights the importance of the atomic structure design of oxygen electrocatalysts for ultralow-temperature and high-capacity ZABs but also spurs the development of sustainable Zn-based batteries at harsh conditions.
It is a great challenge to develop highly active oxygen evolution reaction (OER) electrocatalysts with superior durability. In this study, a NiFe layered double hydroxidedecorated phosphide (NiFe LDH@CoP/NiP 3 ) was constructed to display satisfactory OER activity and good stability for water splitting in alkaline media. At an overpotential of 300 mV, NiFe LDH@CoP/NiP 3 achieved a current density of 82 mA cm −2 for the OER, which was 9.1 and 2.3 times that of CoP/NiP 3 and NiFe LDH, respectively. Moreover, the reconstruction behavior, during which oxyhydroxides formed, was studied by a combination of X-ray photoelectron spectroscopy, Raman spectroscopy, and scanning electron microscopy. A synergistic effect between NiFe LDH and CoP/NiP 3 was also observed for the hydrogen evolution reaction. Furthermore, when NiFe LDH@CoP/NiP 3 acted as both the cathode and anode for overall water splitting, a high current density of 100 mA cm −2 was maintained for more than 275 h.In addition, under Xe light irradiation, a solar-to-hydrogen efficiency of 9.89% was achieved for solar-driven water splitting. This work presents the coupling of different active compositions, and can provide a reference for designing bifunctional electrocatalysts.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.