The safety aspect of sodium ion batteries for practical applications

Sodium-ion batteries(SIBs)with advantages of abundant resource and low cost have emerged as promising candidates for the next-generation energy storage systems.However,safety issues existing in electrolytes,anodes,and cathodes bring about frequent accidents regarding battery fires and explosions and impede the development of high-performance SIBs.Therefore,safety analysis and high-safety battery design have become prerequisites for the development of advanced energy storage systems.The reported reviews that only focus on a specific issue are difficult to provide overall guidance for building high-safety SIBs.To overcome the limitation,this review summarizes the recent research progress from the perspective of key components of SIBs for the first time and evaluates the characteristics of various improvement strategies.By orderly analyzing the root causes of safety problems associated with different components in SIBs(including electrolytes,anodes,and cathodes),corresponding improvement strategies for each component were discussed systematically.In addition,some noteworthy points and perspectives including the chain reaction between security issues and the selection of improvement strategies tailored to different needs have also been proposed.In brief,this review is designed to deepen our understanding of the SIBs safety issues and provide guidance and assistance for designing high-safety SIBs.

The prospect and challenges of sodium-ion batteries for low-temperature conditions

In recent years,considerable attention has been focused on the development of sodium-ion batteries(SIBs)because of the natural abundance of raw materials and the possibility of low cost,which can alleviate the concerns of the limited lithium resources and the increasing cost of lithium-ion batteries.With the growing demand for reliable electric energy storage devices,requirements have been proposed to further increase the comprehensive performance of SIBs.Especially,the low-temperature tolerance has become an urgent technical obstacle in the practical application of SIBs,because the low operating temperature will lead to sluggish electrochemical reaction kinetics and unstable interfacial reactions,which will deteriorate the performance and even cause safety issues.On the basis of the charge-storage mechanism of SIBs,optimization of the composition and structure of electrolyte and electrode materials is crucial to building SIBs with high performance at low temperatures.In this review,the recent research progress and challenges were systematically summarized in terms of electrolytes and cathode and anode materials for SIBs operating at low temperatures.The typical full-cell configurations of SIBs at low temperatures were introduced to shed light on the fundamental research and the exploitation of SIBs with high performance for practical applications.

A nanoconcrete welding strategy for constructing high-performance wound dressing

Engineering biomaterials to meet specific biomedical applications raises high requirements of mechanical performances,and simultaneous strengthening and toughening of polymer are frequently necessary but very challenging in many cases.In this work,we propose a new concept of nanoconcrete welding polymer chains,where mesoporous CaCO3(mCaCO_(3))nanoconcretes which are composed of amorphous and nanocrystalline phases are developed to powerfully weld polymer chains through siphoning-induced occlusion,hydration-driven crystallization and dehydration-driven compression of nanoconcretes.The mCaCO_(3) nanoconcrete welding technology is verified to be able to remarkably augment strength,toughness and anti-fatigue performances of a model polymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-based porous membrane.Mechanistically,we have revealed polymer-occluded nanocrystal structure and welding-derived microstress which is much stronger than interfacial Van der Waals force,thus efficiently preventing the generation of microcracks and repairing initial microcracks by microcracks-induced hydration,crystallization and polymer welding of mCaCO_(3) nanoconcretes.Constructed porous membrane is used as wound dressing,exhibiting a special nanoplates-constructed surface topography as well as a porous structure with plentiful oriented,aligned and opened pore channels,improved hydrophilicity,water vapor permeability,anti-bacterial and cell adherence,in support of wound healing and skin structural/functional repairing.The proposed nanoconcrete-welding-polymer strategy breaks a new pathway for improving the mechanical performances of polymers.