Atomically bonding Na anodes with metallized ceramic electrolytes by ultrasound welding for high-energy/power solid-state sodium metal batteries

A solid-state sodium metal battery has cut a striking figure in next-generation large-scale energy storage technology on account of high safety,high energy density,and low cost.Nevertheless,the large interfacial resistance and sodium dendrite growth originating from the poor interface contact seriously hinder its practical application.Herein,a modified ultrasound welding was proposed to atomically bond Na anodes and Au-metalized Na_(3)Zr_(2)Si_(2)PO_(12) electrolytes associated with the in situ formation of Na–Au alloy interlayers.Thereupon,intimate Na_(3)Zr_(2)Si_(2)PO_(12)-Au/Na interfaces with a low interfacial resistance(~23Ωcm^(2))and a strong dendrite inhibition ability were constructed.The optimized Na symmetric battery can cycle steadily for more than 900 h at 0.3 mA cm^(-2) under a low overpotential(<50 mV)of Na electroplating/stripping and deliver a high critical current density of 0.8 mAcm^(-2) at room temperature.By incorporating the above interface into the solid-state Na metal battery,taking three-dimensional Na_(3)V_(2)(PO_(4))_(3) as the cathode,the full battery offers a high energy density of 291 Wh kg^(-1) at a high power density of 1860Wkg^(-1).A pouch-type solid-state sodium metal full battery based on a ceramic electrolyte was assembled for the first time,and it lit a 3 V LED lamp.Such a strategy of the ultrasound welding metalized solid-state electrolyte/Na interface by engineering the Na-Au interlayer would pave a new pathway to engineer a low-resistance and highly stable interface for high-energy/density solid-state sodium metal batteries.

Construction of S-scheme MnO_(2)@CdS heterojunction with core–shell structure as H_(2)-production photocatalyst

Artificial photosynthesis is deemed as an efficient protocol for transforming abundant solar energy into valuable fuel. In this paper, the well-defined one-dimensional(1D) core–shell MnO_(2)@CdS hybrids were constructed by employing MnO_(2) nanotubes and CdS nanoparticles as nano-building blocks via a chemical coprecipitation route. The rationally designed core–shell structure provided an intimate heterojunction interface between the CdS shell and MnO_(2) core. All the MnO_(2)@CdS core–shell nanocomposites possess higher H_(2) evolution rate through visible light irradiation contrary to pristine CdS, and the optimal MnO_(2)@CdS hybrid exhibits the utmost H_(2) evolution rate of 3.94 mmol·g^(-1)·h^(-1), which is2.8-fold higher compared with that of CdS. Appertaining to XPS and Mott-Schottky(M-S) analysis, such enhanced photocatalytic H_(2) generation of MnO_(2)@CdS heterojunction was ascribed to an S-scheme mechanism, which suppressed the charge recombination along with a fast detachment of electron–hole pairs(e^(-)–h^(+)) and significantly improved the severance of carriers, thus improved H_(2) evolution performance. These findings envision a new insight into the development of S-scheme heterostructure for photocatalytic H_(2) generation.

Modulation of internal electric field engineering of bifunctional multi-interfacial heterojunction photocatalysts for photocatalytic H2 and H_(2)O_(2)production

The purposeful construction of dual Z-scheme system to the formation of intimate interface contact and multi-channel charge flow through the system remains a huge challenge.Herein,a tandem 2D/0D/2D g-C_(3)N_(4)nanosheets/FeOOH quantum dots/ZnIn_(2)S_(4)nanosheets(CNFeZn)dual Z-scheme system(DZSS)has been successfully constructed using electrostatic self-assembly method.Owing to the band structure and elaborate morphology of 2D g-C_(3)N_(4),0D FeOOH and 2D ZnIn_(2)S_(4)in unique designed DZSS,plenty of spatial charge transfer channels are formed between the g-C_(3)N_(4)/FeOOH and FeOOH/ZnIn_(2)S_(4)interfaces,which greatly accelerate the charge separation and transfer.As bifunctional catalysts,CNFeZn DZSS achieves the highest H_(2)evolution rate of~436.6 mmol/h with a great promotion of~10.6 folds and~6.9 folds compared to pristine g-C_(3)N_(4)and ZnIn_(2)S_(4),respectively.Meanwhile,the H_(2)O_(2)production rate reached~301.19 mmol/L after 60 min irradiation,up to~5.1 times and~2.3 times that of pristine g-C_(3)N_(4)and ZnIn_(2)S_(4).Experiment and DFT calculation further confirmed that the stable double built-in electronic field can be formed owing to the electron configuration between double interfaces,and reveal that the ample atomic-level charge transfer channels were established in the strong interaction connected double interfaces,which can act as the charge migration pathway promote the separation of photogenerated charges.