Direct Regeneration of Spent Lithium-Ion Battery Cathodes:From Theoretical Study to Production Practice

Direct regeneration method has been widely concerned by researchers in the field of battery recycling because of its advantages of in situ regeneration,short process and less pollutant emission.In this review,we firstly analyze the primary causes for the failure of three representative battery cathodes(lithium iron phosphate,layered lithium transition metal oxide and lithium cobalt oxide),targeting at illustrating their underlying regeneration mecha-nism and applicability.Efficient stripping of material from the collector to obtain pure cathode material has become a first challenge in recycling,for which we report several pretreatment methods currently available for subsequent regeneration processes.We review and discuss emphatically the research progress of five direct regeneration methods,including solid-state sintering,hydrothermal,eutectic molten salt,electrochemical and chemical lithiation methods.Finally,the application of direct regeneration technology in production practice is introduced,the problems exposed at the early stage of the industrialization of direct regeneration technol-ogy are revealed,and the prospect of future large-scale commercial production is proposed.It is hoped that this review will give readers a comprehensive and basic understanding of direct regeneration methods for used lithium-ion batteries and promote the industrial application of direct regeneration technology.

From Wallpaper to Interactivity： Use of Archive Footage in Documentary Filmmaking

＂Our relation to the past is being transformed by digital media. Internet and digital databases increase the presence of the past and remake our connection to both past and present＂ （Manoff, 2010, p. 9）. The use of archive footage in documentary filmmaking has increased significantly, since the digitalization of audio-visual archives. Access is facilitated by databases and different interfaces. The theorization about the particular impacts of archive footage on the documentary text has not received much attention as yet as archive usage has been seen as unproblematic and digital archives as just ＂handy＂. This paper is a first step in the development of a taxonomy of how archive footage is being used by documentary filmmakers, while taken into account the production practices and the processes of archivization of archive materials.

Discussion on the Teaching Concept of Major Production Practice

College students’major production practice is an important part of practical teaching in colleges and universities,a key link of major teaching system,a necessary link of undergraduate teaching training program and teaching plan,and an important form of combining classroom education with social practice.In order to meet the actual needs of college students’major production practice,this paper proposes the key links of establishing strategic cooperation relationship with enterprises and institutions by industry university research channels,ensuring the construction of practice base,changing the ideas of teachers and students,stimulating students’internal motivation,maintaining the goal of professional characteristics,adhering to the exploration of professional characteristics,strengthening the cultivation of comprehensive ability and improving the assessment mechanism of production practice to ensure the high quality of college students’major production practice and achieve the purpose of practice.

Yinguizhan developed by the Rice Res Inst of Guizhou Acad of Agri Sci

Editor-in-chief(?) Prof DINa yuanshu In Chinese.