采用固态电解质代替有机电解液的全固态电池具有高能量密度和高安全性等优点,为下一代能量存储设备提供了一种很有发展前途的解决方案.然而,大多数固态电解质和电极活性物质间都存在严重的界面问题,制约固态电池的实际应用;解决固态电池中的固-固界面问题,提升固态电池电化学性能是目前的研究热点.本文详细总结了固态电池中的界面挑战、改善策略以及针对界面问题的表征方法,并展望了固态电池今后发展中的关键方向和趋势.“,”Owing to the serious energy crisis and environmental problems caused by fossil energy consumption,development of high-energy-density batteries is becoming increasingly significant to satisfy the rapidly growing social demands.Lithium-ion batteries have received widespread attention because of their high energy densities and environmental friendliness.At present,they are widely used in portable electronic devices and electric vehicles.However,security aspects need to be addressed urgently.Substantial advances in liquid electrolyte-based lithium-ion batteries have become a performance bottleneck in the recent years.Traditional lithium-ion batteries use organic liquids as electrolytes,but the flammability and corrosion of these electrolytes considerably limit their development.Continuous growth of lithium dendrites can pierce the separator,leading to electrolyte leakage and combustion,which is a serious safety hazard.Replacement of organic electrolytes with solid-state electrolytes is one of the promising solutions for the development of next-generation energy storage devices,because they have high energy densities and are safe.Solid electrolytes can remarkably alleviate the safety hazards involved in the use of traditional liquid-based lithium-ion batteries.In addition,the composite of solid-state electrolytes and lithium metal is expected to result in a higher energy density.However,due to the lack of fluidity of the solid electrolytes,problems such as limited solid-solid contact area and increased impedance at the interface when solid-state electrolytes are in contact with electrodes must be solved.The localized and buried interface is a major drawback that restricts the electrochemical performance and practical applications of the solid-state batteries.Fabrication of a stable interface between the electrodes and solid-state electrolyte is the main challenge in the development of solid-state lithium metal batteries.All these aspects are critical to the electrochemical performance and safety of the solid-state batteries.Current research mainly focuses on addressing the problems related to the solid-solid interface in solid-state batteries and improving the electrochemical performance of such batteries.In this review,we comprehensively summarize the challenges in the fabrication of solid-state batteries,including poor chemical and electrochemical compatibilities and mechanical instability.Research progress on the improvement strategies for interface problems and the advanced characterization methods for the interface problems are discussed in detail.Meanwhile,we also propose a prospect for the future development of solid-state batteries to guide the rational designing of next-generation high-energy solid-state batteries.There are many critical problems in solid-state batteries that must be fully understood.With further research,all-solid-state batteries are expected to replace the traditional liquid-based lithium-ion batteries and become an important system for a safe and reliable energy storage.