Poly(ethylene oxide) (PEO) is a promising solid electrolyte material for solidstate lithium-sulfur (Li-S) batteries, but low intrinsic ionic conductivity, poor mechanical properties, and failure to hinder the polysulfide shuttle effect limits its application. Herein, a polymer of intrinsic microporosity (PIM) is synthesized and applied as an organic framework to comprehensively enhance the performance of PEO by forming a composite electrolyte (PEO-PIM). The unique structure of PIM-1 not only enhances the mechanical strength and hardness over the PEO electrolyte by an order of magnitude, increasing stability toward the metallic lithium anode but also increases its ionic conductivity by lowering the degree of crystallinity. Furthermore, the PIM-1 is shown to effectively trap lithium polysulfide species to mitigate against the detrimental polysulfide shuttle effect, as electrophilic 1,4-dicyanooxanthrene functional groups possess higher binding energy to polysulfides. Benefiting from these properties, the use of PEO-PIM composite electrolyte has achieved greatly improved rate performance, long-cycling stability, and excellent safety features for solid-state Li-S batteries. This methodology offers a new direction for the optimization of solid polymer electrolytes.

Straighthead disease is a physiological disorder in rice with symptoms of sterile spikelets, distorted husks, and erect panicles. Methylated arsenic species have been implicated as the causal agent of the disease, but direct evidence is lacking. Here, we investigated whether dimethylarsinic acid (DMA) causes straighthead disease and its effect on the transcriptome of young panicles. DMA addition caused typical straighthead symptoms in hydroponic culture, which were alleviated by silicon addition. DMA addition to soil at the tillering to flowering stages induced straighthead disease. Transgenic rice expressing a bacterial arsenite methyltransferase gene gained the ability to methylate arsenic to mainly DMA, with the consequence of inducing straighthead disease. Field surveys showed that seed setting rate decreased with increasing DMA concentration in the husk, with an EC50 of 0.18 mg kg−1. Transcriptomic analysis showed that 364 and 856 genes were significantly up- and down-regulated, respectively, in the young panicles of DMA-treated plants compared with control, whereas Si addition markedly reduced the number of genes affected. Among the differentially expressed genes, genes related to cell wall modification and oxidative stress responses were the most prominent, suggesting that cell wall metabolism is a sensitive target of DMA toxicity and silicon protects against this toxicity.

This tutorial review presents the fundamentals of EQCM, and recent achievements in the bulk phenomena and interfacial mechanisms in batteries revealed by the EQCM technique.

Poly(ethylene oxide) (PEO)-based solid polymer electrolyte (SPE) is considered as a promising solid-state electrolyte for all-solid-state lithium batteries (ASSLBs). Nevertheless, the poor interfacial stability with high-voltage cathode materials (e.g., LiCoO2) restricts its application in high energy density solid-state batteries. Herein, high-voltage stable Li3AlF6 protective layer is coated on the surface of LiCoO2 particle to improve the performance and investigate the failure mechanism of PEO-based ASSLBs. The phase transition unveils that chemical redox reaction occurs between the highly reactive LiCoO2 surface and PEO-based SPE, resulting in structure collapse of LiCoO2, hence the poor cycle performance of PEO-based ASSLBs with LiCoO2 at charging voltage of 4.2 V vs Li/Li+. By sharp contrast, no obvious structure change can be found at the surface of Li3AlF6-coated LiCoO2, and the original layered phase was well retained. When the charging voltage reaches up to 4.5 V vs Li/Li+, the intensive electrochemical decomposition of PEO-based SPE occurs, leading to the constant increase of cell impedance and directly causing the poor performance. This work not only provides important supplement to the failure mechanism of PEO-based batteries with LiCoO2, but also presents a universal strategy to retain structure stability of cathode–electrolyte interface in high-voltage ASSLBs.

No abstract