While sulfide solid electrolytes such as Na₁₁Sn₂PS₁₂ can allow fast transport of Na⁺ ions, their utilization in solid sodium ion batteries is rather unsuccessful since they are not electrochemically compatible to both high-voltage cathodes and sodium metal anode. In this work, we devise an effective approach toward realizing solid sodium ion batteries, using the Na₁₁Sn₂PS₁₂ electrolyte and slurry-coated NASICON-type Na₃MnTi(PO₄)₃@C as high-voltage cathode, highly beneficial for low processing cost and high content/loading of active cathode matter. We report that through significantly improved integrity of electrolyte-cathode interface, such solid sodium ion batteries can deliver outstanding cycling and rate performance, with a charge voltage resilience up to 4.1 V, a high cathode discharge capacity of 128.7 mAh g⁻¹ against the Na₃MnTi(PO₄)₃@C in cathode is achieved at 0.05 C, and capacity retention ratio of 82% with a rate of 0.1 C is realized after prolonged cycling at room temperature. Besides, we demonstrate that such a solid sodium ion battery can even perform at a sub-zero Celsius temperature of −10°C, when the conventional control cell using liquid electrolyte completely fail to function. This work is to offer a dependable avenue in engineering next generation of safe solid ion batteries based on highly sustainable and much cheaper material resources.

All-inorganic CsPbBr₃-based perovskite solar cells (PSCs) have attracted great attention because of their high chemical and thermal stabilities in ambient air. However, the short-circuit current density (J_sc) of CsPbBr₃-based PSCs is inadequate under solar illumination because of the wide bandgap, inefficient charge extraction and recombination loss, leading to lower power-conversion efficiencies (PCEs). It is envisaged that in addition to narrowing the bandgap by alloying, J_sc of the PSCs could be enhanced by effective improvement of electron transportation, suppression of charge recombination at the interface between the perovskite and electron transporting layer (ETL), and tuning of the space charge field in the device. In this work, Nb-doped SnO₂ films as ETLs in the CsPbBr₃-based PSCs have been deposited at room temperature by high target utilization sputtering (HiTUS). Through optimizing the Nb doping level alone, the J_sc was increased by nearly 19%, from 7.51 to 8.92 mA·cm⁻² and the PCE was enhanced by 27% from 6.73% to 8.54%. The overall benefit by replacing the spin-coated SnO₂ with sputtered SnO₂ with Nb doping was up to 39% increase in J_sc and 62% increase in PCE. Moreover, the PCE of the optimized device showed negligible degradation over exposure to ambient environment (T ~ 25 ℃, RH~45%), with 95.4% of the original PCE being maintained after storing the device for 1200 h.

Heteroatom doped graphene materials are considered as promising anode for high-performance sodium-ion batteries (SIBs). Defective and porous structure especially with large specific surface area is generally considered as a feasible strategy to boost reaction kinetics; however, the unwanted side reaction at the anode hinders the practical application of SIBs. In this work, a precisely controlled Al₂O₃ coated nitrogen doped vertical graphene nanosheets (NVG) anode material has been proposed, which exhibits excellent sodium storage capacity and cycling stability. The ultrathin Al₂O₃ coating on the NVG is considered to help construct an advantageous interface between electrode and electrolyte, both alleviating the electrolyte decomposition and enhancing sodium adsorption ability. As a result, the optimal Al₂O₃ coated NVG materials delivers a high reversible capacity (835.0 mAh g⁻¹) and superior cycling stability (retention of 92.3% after 5000 cycles). This work demonstrates a new way to design graphene-based anode materials for high-performance sodium-ion batteries.