Sulfolane‑Based Flame‑Retardant Electrolyte for High‑Voltage Sodium‑Ion Batteries

Sodium-ion batteries hold great promise as next-generation energy storage systems.However,the high instability of the electrode/electrolyte interphase during cycling has seriously hindered the development of SIBs.In particular,an unstable cathode–electrolyte interphase(CEI)leads to successive electrolyte side reactions,transition metal leaching and rapid capacity decay,which tends to be exacerbated under high-voltage conditions.Therefore,constructing dense and stable CEIs are crucial for high-performance SIBs.This work reports localized high-concentration electrolyte by incorporating a highly oxidation-resistant sulfolane solvent with non-solvent diluent 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether,which exhibited excellent oxidative stability and was able to form thin,dense and homogeneous CEI.The excellent CEI enabled the O3-type layered oxide cathode NaNi_(1/3)Mn_(1/3)Fe_(1/3)O_(2)(NaNMF)to achieve stable cycling,with a capacity retention of 79.48%after 300 cycles at 1 C and 81.15%after 400 cycles at 2 C with a high charging voltage of 4.2 V.In addition,its nonflammable nature enhances the safety of SIBs.This work provides a viable pathway for the application of sulfolane-based electrolytes on SIBs and the design of next-generation high-voltage electrolytes.

Excellent ductility and serration feature of metastable CoCrFeNi high-entropy alloy at extremely low temperatures

Seldom could metals and alloys maintain excellent properties in cryogenic condition, such as the ductility, owing to the restrained dislocation motion.However, a face-centered-cubic(FCC) CoCrFeNi highentropy alloy(HEA) with great ductility is investigated under the cryogenic environment. The tensile strength of this alloy can reach a maximum at 1,251±10 MPa, and the strain to failure can stay at as large as 62% at the liquid helium temperature. We ascribe the high strength and ductility to the low stacking fault energy at extremely low temperatures,which facilitates the activation of deformation twinning.Moreover, the FCC→HCP(hexagonal close-packed) transition and serration lead to the sudden decline of ductility below 77 K. The dynamical modeling and analysis of serrations at 4.2 and 20 K verify the unstable state due to the FCC→HCP transition. The deformation twinning together with phase transformation at liquid helium temperature produces an adequate strain-hardening rate that sustains the stable plastic flow at high stresses, resulting in the serration feature.

Symplastic communication in the root cap directs auxin distribution to modulate root development

Root cap not only protects root meristem,but also detects and transduces the signals of environmental changes to affect root development.The symplastic communication is an important way for plants to transduce signals to coordinate the development and physiology in response to the changing enviroments.However,it is unclear how the symplastic communication between root cap cells affects root growth.Here we exploit an inducible system to specifically block the symplastic communication in the root cap.Transient blockage of plasmodesmata(PD)in differentiated collumella cells severely impairs the root development in Arabidopsis,in particular in the stem cell niche and the proximal meristem.The neighboring stem cell niche is the region that is most sensitive to the disrupted symplastic communication and responds rapidly via the alteration of auxin distribution.In the later stage,the cell division in proximal meristem is inhibited,presumably due to the reduced auxin level in the root cap.Our results reveal the essential role of the differentiated collumella cells in the root cap mediated signaling system that directs root development.