RESUMO
Owing to the high volumetric capacity and low redox potential, zinc (Zn) metal is considered to be a remarkably prospective anode for aqueous Zn-ion batteries (AZIBs). However, dendrite growth severely destabilizes the electrode/electrolyte interface, and accelerates the generation of side reactions, which eventually degrade the electrochemical performance. Here, an artificial interface film of nitrogen (N)-doped graphene oxide (NGO) is one-step synthesized by a Langmuir-Blodgett method to achieve a parallel and ultrathin interface modification layer (≈120 nm) on Zn foil. The directional deposition of Zn crystal in the (002) planes is revealed because of the parallel graphene layer and beneficial zincophilic-traits of the N-doped groups. Meanwhile, through the in situ differential electrochemical mass spectrometry and in situ Raman tests, the directional plating morphology of metallic Zn at the interface effectively suppresses the hydrogen evolution reactions and passivation. Consequently, the pouch cells pairing this new anode with LiMn2 O4 cathode maintain exceptional energy density (164 Wh kg-1 after 178 cycles) at a reasonable depth of discharge, 36%. This work provides an accessible synthesis method and in-depth mechanistic analysis to accelerate the application of high-specific-energy AZIBs.
RESUMO
Phytoplankton have a complex life-cycle. Resting cysts are formed like terrestrial plants. Cysts play important roles in resisting environmental pressure, surviving adverse environment, maintaining physiological homeostasis, and maintaining species reproduction. In some ecological events, cysts were served as "seed bank" for periodical algal blooming. However, compared with the mature cells, the ecophysiological research on cysts is relatively limited. To deepen our understanding on life-cycle and ecological roles of cysts, we reviewed the researches on cysts in the past two decades. Firstly, we outlined the types (resting cysts, zoocysts, mature cysts) and factors that affected the formation of cysts of typical dinoflagellates and diatoms. Secondly, we summarized the formation mechanism, physiological characteristics and germination factors of cysts. Finally, we discussed the significance of cysts in algal evolution and in ocean carbon cycle. This review, summarizing the adaptability and plasticity of cysts, would shed light on ecological mechanism of algae survival strategy.