锂离子电池硅基负极黏合剂的研究进展

硅(Si)基负极因具有超高的理论比容量(4200 mAh/g),有望替代石墨电极(理论比容量372 mAh/g)成为新一代的高容量锂离子电池负极。但Si负极在电池循环过程中所引起的巨大体积膨胀,会导致Si颗粒的粉碎、电接触失效及其它副反应,最终导致电池容量的快速衰减以及循环稳定性变差。黏合剂是锂离子电池负极的重要组成部分之一,虽然含量很少,但在稳定电极循环中起着关键作用。文中主要对Si基负极电池黏合剂的溶剂类型及聚合结构(包括线型、交联以及共轭导电聚合物)进行了分类,并在黏合机理、优点、局限性以及性能等方面进行了阐述,最后对亟待深入研究的方向和发展前景进行了展望。

A phase inversion based sponge-like polysulfonamide/SiO_2 composite separator for high performance lithium-ion batteries

In this work,a sponge-like polysulfonamide(PSA)/SiO_2 composite membrane is unprecedentedly prepared by the phase inversion method,and successfully demonstrated as a novel separator of lithium-ion batteries(LIBs).Compared to the commercial polypropylene(PP) separator,the sponge-like PSA/SiO_2 composite possesses better physical and electrochemical properties,such as higher porosity,ionic conductivity,thermal stability and flame retarding ability.The LiCoO_2/Li half-cells using the sponge-like composite separator demonstrate superior rate capability and cyclability over those using the commercial PP separator.Moreover,the sponge-like composite separator can ensure the normal operation of LiCoO_2/Li half-cell at an extremely high temperature of 90 °C,while the commercial PP separator cannot.All these encouraging results suggest that this phase inversion based sponge-like PSA/SiO_2 composite separator is really a promising separator for high performance LIBs.

Lithium bis(oxalate)borate crosslinked polymer electrolytes for high-performance lithium batteries

Solid electrolytes play a vital role in solid-state Li secondary batteries,which are promising high-energy storage devices for new-generation electric vehicles.Nevertheless,obtaining a suitable solid electrolyte by a simple and residue-free preparation process,resulting in a stable interface between electrolyte and electrode,is still a great challenge for practical applications.Herein,we report a self-crosslinked polymer electrolyte(SCPE)for high-performance lithium batteries,prepared by a one-step method based on 3-methoxysilyl-terminated polypropylene glycol(SPPG,a liquid oligomer).It is worth noting that lithium bis(oxalate)borate(Li BOB)can react with SPPG to form a crosslinked structure via a curing reaction.This self-formed polymer electrolyte exhibits excellent properties,including high roomtemperature ionic conductivity(2.6×10^(-4) S cm^(-1)),wide electrochemical window(4.7 V),and high Li ion transference number(0.65).The excellent cycling stability(500 cycles,83%)further highlights the improved interfacial stability after the in situ formation of SCPE on the electrode surface.Moreover,this self-formation strategy enhances the safety of the battery under mechanical deformation.Therefore,the present self-crosslinked polymer electrolyte shows great potential for applications in high-performance lithium batteries.

The correlation between ultrasonographic findings and the Lysholm scores in knee osteoarthritis

Objective:To analyze the correlation between ultrasonographic findings and Lysholm scores in knee osteoarthritis.Methods:This cross-sectional observational study included 77 cases of knee osteoarthritis examined from February to December in 2015.There were 66 females and 11 males,with an average age of 57.39 (6.41) years,single or bilateral knee pain and limitation of mobility,and an average course of disease of 13.60 (3.00) months.Multiple regression equations were applied in a linear regression analysis to assess the correlation between ultrasound findings and Lysholm scores.Results:The ultrasonographic findings of joint effusion,synovial hypertrophy,protrusion of the medial meniscus (MMP),and inflammation of subpatellar fat pad were significantly correlated with the Lysholm scores (all P <.05).In contrast,there was no association between the ultrasonographic findings of Baker's cyst or patellar ligament lesion and the Lysholm scores (both P >.05).Conclusion:Musculoskeletal ultrasound can better detect the pathological changes of soft tissue in the knee,mainly including synovial hypertrophy,joint effusion,and MMP in comparison with those by plain radiology.After statistical analysis,it is indicated that ultrasonographic findings of synovial hypertrophy was possibly associated with joint locking,joint effusion with supporting,MMP with squatting,and inflammation of subpatellar fat pad with squatting and locking.

Production and Utilization of L-Arabinose in China

L-arabinose is a newly developed low-caloric monosaccharide, which has many biomedical and health effects, especially intestinal sucrase inhibition effect. L-arabinose is mainly produced by chemical or enzymatic hydrolysis of hemicellulose. The taste of L-arabinose is quite similar to that of sucrose, with approximately 50% of the sweetness. As a functional additive, L-arabinose can be used in medical and pharmaceutical applications for the treatment of diseases such as diabetes, chronic constipation, mineral absorption disorder and secondary bile acid formation disorder. However, L-arabinose has not been widely used in functional foods due to high price and lack of publicity and guidance. A comprehensive review of L-arabinose physicochemical properties, production, applications field, market statue and development direction is presented in this paper.

Identification and analysis of key microRNAs derived from osteoarthritis synovial fluid exosomes

To the Editor:Osteoarthritis(OA)is one of the most common age-related diseases and is characterized by synovial inflammation and progressive degradation of cartilage.It was reported that one-third of 65-year-olds and 303 million people globally were affected by OA in 2017.[1,2]Although there is extensive research published on OA,its pathogenesis remains unclear and controversial.Cartilage degeneration is considered a key pathological factor that leads to disease progression.

Oral microbiota accelerates corrosion of 316L stainless steel for orthodontic applications

In this work,microbiologically influenced corrosion(MIC)of 316 L stainless steel(SS)caused by oral microbiota was investigated with HOMINGS 16 S rRNA gene sequencing technology,and electrochemical and surface analysis techniques.The results showed that oral microbiota from different subjects developed multi-species biofilms with significant differences in structure and composition of bacteria strains on the316 L SS coupons.In the presence of oral microbiota,more severe pitting corrosion and faster dissolution of metallic ions including Ni and Cr were observed.The biofilm considerably decreased the pitting potential of 316 L SS from 1268.0±29.1 mV vs.SCE(abiotic control)to less than 500 mV vs.SCE.The corrosion current density in the presence of oral microbiota from subject 1(115.3±83.3 nA cm^(-2))and subject 2(184.4±162.0 nA cm^(-2))was at least 4 times more than that in the abiotic medium(28.0±2.3 nA cm^(-2)).The electroactive microorganisms with the potential to facilitate corrosion via extracellular electron transfer found in oral microbiota may be mainly responsible for the accelerated corrosion.