Smart materials for safe lithium-ion batteries against thermal runaway

In recent years,the new energy storage system,such as lithium ion batteries(LIBs),has attracted much attention.In order to meet the demand of industrial progress for longer cycle life,higher energy density and cost efficiency,a quantity of research has been conducted on the commercial application of LIBs.However,it is difficult to achieve satisfying safety and cycling performance simultaneously.There may be thermal runaway(TR),external impact,overcharge and overdischarge in the process of battery abuse,which makes the safety problem of LIBs more prominent.In this review,we summarize recent progress in the smart safety materials design towards the goal of preventing TR of LIBs reversibly from different abuse conditions.Benefiting from smart responsive materials and novel structural design,the safety of LIBs can be improved a lot.We expect to provide a comprehensive reference for the development of smart and safe lithium-based battery materials.

Recent Advances in Electrolytes for High-Voltage Cathodes of Lithium-Ion Batteries

With the increasing scale of energy storage,it is urgently demanding for further advancements on battery technologies in terms of energy density,cost,cycle life and safety.The development of lithium-ion batteries(LIBs)not only relies on electrodes,but also the functional electrolyte systems to achieve controllable formation of solid electrolyte interphase and high ionic conductivity.In order to satisfy the needs of higher energy density,high-voltage(>4.3 V)cathodes such as Li-rich layered compounds,olivine LiNiPO_(4),spinel LiNi_(0.5)Mn_(1.5)O_(4) have been extensively studied.However,high-voltage cathodebased LIBs fade rapidly mainly owing to the anodic decomposition of electrolytes,gradually thickening of interfacial passivation layer and vast irreversible capacity loss,hence encountering huge obstacle toward practical applications.To tackle this roadblock,substantial progress has been made toward oxidation-resistant electrolytes to block its side reaction with high-voltage cathodes.In this review,we discuss degradation mechanisms of electrolytes at electrolyte/cathode interface and ideal requirements of electrolytes for high-voltage cathode,as well as summarize recent advances of oxidation-resistant electrolyte optimization mainly from solvents and additives.With these insights,it is anticipated that development of liquid electrolyte tolerable to high-voltage cathode will boost the large-scale practical applications of high-voltage cathode-based LIBs.

Strategies for flame-retardant polymer electrolytes for safe lithiumbased batteries

The advancement of lithium-based batteries has spurred anticipation for enhanced energy density,extended cycle life and reduced capacity degradation.However,these benefits are accompanied by potential risks,such as thermal runaway and explosions due to higher energy density.Currently,liquid organic electrolytes are the predominant choice for lithium batteries,despite their limitations in terms of mechanical strength and vulnerability to leakage.The development of polymer electrolytes,with their high Young’s modulus and enhanced safety features,offers a potential solution to the drawbacks of traditional liquid electrolytes.Despite these advantages,polymer electrolytes are still susceptible to burning and decomposition.To address this issue,researchers have conducted extensive studies to improve their flame-retardant properties from various perspectives.This review provides a concise overview of the thermal runaway mechanisms,flame-retardant mechanisms and electrochemical performance of polymer electrolytes.It also outlines the advancements in flame-retardant polymer electrolytes through the incorporation of various additives and the selection of inherently flame-retardant matrix.This review aims to offer a comprehensive understanding of flame-retardant polymer electrolytes and serve as a guide for future research in this field.

Enhanced detection algorithm for apple bruises using structured light imaging

Bruising reduces the edibility and marketability of fresh apples,inevitably causing economic losses for the apple industry.However,bruises lack obvious visual symptoms,which makes it challenging to detect them using imaging techniques with uniform or diffuse illumination.This study employed the structured light imaging(SLI)technique to detect apple bruises.First,the grayscale reflection images were captured under phase-shifted sinusoidal illumination at three different wavelengths(600,650,and 700 nm)and six different spatial frequencies(0.05,0.10,0.15,0.20,0.25,and 0.30 cycles mm−1).Next,the grayscale reflectance images were demodulated to produce direct component(DC)images representing uniform diffuse illumination and amplitude component(AC)images revealing bruises.Then,by quantifying the contrast between bruised regions and sound regions in all AC images,it was found that bruises exhibited the optimal contrast when subjected to sinusoidal illumination at a wavelength of 700 nm and a spatial frequency of 0.25 mm−1.In the AC image with optimal contrast,the developed h-domes segmentation algorithm to accurately segment the location and range of the bruised regions.Moreover,the algorithm successfully accomplished the task of segmenting central bruised regions while addressing the challenge of segmenting edge bruised regions complicated by vignetting.The average Intersection over Union(IoU)values for the three types of bruises were 0.9422,0.9231,and 0.9183,respectively.This result demonstrated that the combination of SLI and the h-domes segmentation algorithm was a viable approach for the effective detection of fresh apple bruises.

Bi_(2)S_(3) nanorods encapsulated in iodine-doped graphene frameworks with enhanced potassium storage properties

Bismuth sulfide(Bi_(2)S_(3))is a promising anode material for high-performance potassium ion batteries due to its high theoretical capacity.However,the poor conductivity and substantial volume expansion hinder its practical application.We proposed an iodine-doped graphene encapsulated Bi_(2)S_(3)nanorods composite(Bi_(2)S_(3)/IG)as an efficient anode for PIBs.The uniform-sized Bi_(2)S_(3)nanorods evenly in-situ encapsulated in iodine-doped graphene framework,facilitating the electron transportation and structural stability.The potassium storage performance was evaluated in three electrolytes,with the best option of 5 mol/L KFSI in DME.The reversible capacity of representative Bi_(2)S_(3)/IG reached 453.5 m Ah/g at 50 m A/g.Meanwhile,it could deliver an initial reversible capacity of 413.6 m Ah/g at 100 m A/g,which maintained 256.9 m Ah/g after 200 cycles.The proposed strategy contributes to improving potassium storage performance of metal sulfide anodes.