Functional Optical Fiber Sensors Detecting Imperceptible Physical/Chemical Changes for Smart Batteries

The battery technology progress has been a contradictory process in which performance improvement and hidden risks coexist.Now the battery is still a“black box”,thus requiring a deep understanding of its internal state.The battery should“sense its internal physical/chemical conditions”,which puts strict requirements on embedded sensing parts.This paper summarizes the application of advanced optical fiber sensors in lithium-ion batteries and energy storage technologies that may be mass deployed,focuses on the insights of advanced optical fiber sensors into the processes of one-dimensional nano-micro-level battery material structural phase transition,electrolyte degradation,electrode-electrolyte interface dynamics to three-dimensional macro-safety evolution.The paper contributes to understanding how to use optical fiber sensors to achieve“real”and“embedded”monitoring.Through the inherent advantages of the advanced optical fiber sensor,it helps clarify the battery internal state and reaction mechanism,aiding in the establishment of more detailed models.These advancements can promote the development of smart batteries,with significant importance lying in essentially promoting the improvement of system consistency.Furthermore,with the help of smart batteries in the future,the importance of consistency can be weakened or even eliminated.The application of advanced optical fiber sensors helps comprehensively improve the battery quality,reliability,and life.

Tailoring Practically Accessible Polymer/Inorganic Composite Electrolytes for All-Solid-State Lithium Metal Batteries:A Review

Solid-state electrolytes(SSEs)are widely considered the essential components for upcoming rechargeable lithium-ion batteries owing to the potential for great safety and energy density.Among them,polymer solid-state electrolytes(PSEs)are competitive candidates for replacing commercial liquid electrolytes due to their flexibility,shape versatility and easy machinability.Despite the rapid development of PSEs,their practical application still faces obstacles including poor ionic conductivity,narrow electrochemical stable window and inferior mechanical strength.Polymer/inorganic composite electrolytes(PIEs)formed by adding ceramic fillers in PSEs merge the benefits of PSEs and inorganic solid-state electrolytes(ISEs),exhibiting appreciable comprehensive properties due to the abundant interfaces with unique characteristics.Some PIEs are highly compatible with high-voltage cathode and lithium metal anode,which offer desirable access to obtaining lithium metal batteries with high energy density.This review elucidates the current issues and recent advances in PIEs.The performance of PIEs was remarkably influenced by the characteristics of the fillers including type,content,morphology,arrangement and surface groups.We focus on the molecular interaction between different components in the composite environment for designing high-performance PIEs.Finally,the obstacles and opportunities for creating high-performance PIEs are outlined.This review aims to provide some theoretical guidance and direction for the development of PIEs.

Polyimides as Promising Materials for Lithium-Ion Batteries:A Review

Lithium-ion batteries(LIBs)have helped revolutionize the modern world and are now advancing the alternative energy field.Several technical challenges are associated with LIBs,such as increasing their energy density,improving their safety,and prolonging their lifespan.Pressed by these issues,researchers are striving to find effective solutions and new materials for next-generation LIBs.Polymers play a more and more important role in satisfying the ever-increasing requirements for LIBs.Polyimides(PIs),a special functional polymer,possess unparalleled advantages,such as excellent mechanical strength,extremely high thermal stability,and excellent chemical inertness;they are a promising material for LIBs.Herein,we discuss the current applications of PIs in LIBs,including coatings,separators,binders,solid-state polymer electrolytes,and active storage materials,to improve high-voltage performance,safety,cyclability,flexibility,and sustainability.Existing technical challenges are described,and strategies for solving current issues are proposed.Finally,potential directions for implementing PIs in LIBs are outlined.

Insight into the Electrochemical Behaviors of NCM811|SiO-Gr Pouch Battery through Thickness Variation

LiNi0.8Co0.1Mn0.1O2(NCM811)|SiOx-graphite(SiO-Gr.)battery chemistry is of intensive attention because its achievable practical energy density is approaching impressively 300 Wh Kg^(-1).However,it still suffers rapid capacity fades during repeated cycles,both chemical,electrochemical and mechanical irreversibility contribute.A comprehensive understanding behind the fading behavior of the cell chemistry is required before fully realize the benefits of this chemistry.Herein,the in-situ thickness variation is introduced as a diagnostic technique and is performed on 5-55 Ah NCM811|SiO-Gr cells.With the help of Li reference electrode and in-situ X-ray diffraction device,the correspondence between thickness variation and the electrode potential is carefully investigated.Firstly,the NCM811|SiO-Gr cell is characterized with the maximum cell thickness at around 80%state-of-charge(SOC)in the discharge process,rather than at 100%SOC.Secondly,the electrochemical behaviors during rate charge/discharge are diagnosed,and a Li platting signal is resolved from thickness variation profile at 2C.This work confirms that the thickness monitoring is a nondestructive and informative complement to conventional diagnostic techniques for failure analysis of pouch cells.

合成条件对锂离子电池正极材料性能的影响

层状过渡金属氧化物正极材料(LiTMO_(2))因其高理论比容量,是高比能量锂离子电池广泛应用的一类正极材料。然而,LiTMO_(2)在脱嵌锂过程中存在的化学-机械协同作用导致电池的循环失效问题突出,阻碍了其进一步发展。研究人员对此失效行为开展了大量研究,并提出掺杂、包覆、表面及晶界改性等各种正极材料改性策略,但是合成过程中形成的晶格缺陷和异质结构往往对此失效行为具有重要影响。因此,深入了解合成过程中各种控制因素对材料结构的影响很有必要。本文旨在阐明合成过程中前驱体、锂盐、烧结温度、保温时间和烧结气氛等因素对LiTMO_(2)材料结构的影响效果及机理,以期为研究者优化合成获得高性能LiTMO_(2)材料提供参考和依据。