Lithium-Ion Charged Polymer Channels Flattening Lithium Metal Anode

The concentration difference in the near-surface region of lithium metal is the main cause of lithium dendrite growth.Resolving this issue will be key to achieving high-performance lithium metal batteries(LMBs).Herein,we construct a lithium nitrate(LiNO_(3))-implanted electroactiveβphase polyvinylidene fluoride-co-hexafluoropropylene(PVDF-HFP)crystalline polymorph layer(PHL).The electronegatively charged polymer chains attain lithium ions on the surface to form lithium-ion charged channels.These channels act as reservoirs to sustainably release Li ions to recompense the ionic flux of electrolytes,decreasing the growth of lithium dendrites.The stretched molecular channels can also accelerate the transport of Li ions.The combined effects enable a high Coulombic efficiency of 97.0%for 250 cycles in lithium(Li)||copper(Cu)cell and a stable symmetric plating/stripping behavior over 2000 h at 3 mA cm^(-2)with ultrahigh Li utilization of 50%.Furthermore,the full cell coupled with PHL-Cu@Li anode and Li Fe PO_(4) cathode exhibits long-term cycle stability with high-capacity retention of 95.9%after 900 cycles.Impressively,the full cell paired with LiNi_(0.87)Co_(0.1)Mn_(0.03)O_(2)maintains a discharge capacity of 170.0 mAh g^(-1)with a capacity retention of 84.3%after 100 cycles even under harsh condition of ultralow N/P ratio of 0.83.This facile strategy will widen the potential application of LiNO_(3)in ester-based electrolyte for practical high-voltage LMBs.

Two-in-one shell configuration for bimetal selenides toward fast sodium storage within broadened voltage windows

The shell structure design has been recognized as a highly efficient strategy to buffer the severe volume expansion and consecutive pulverization of conversion-type anodes.Nevertheless,construction of a functional shell with a stabilized structure that meets the demands of both high electronic conductivity and feasible pathways for Na^(+)ions has been a challenge so far.Herein,we design a two-in-one shell configuration for bimetal selenides to achieve fast sodium storage within broadened voltage windows.The hybridized shell,which benefits from the combination of titanium dioxide quantum dots and amorphous carbon,can not only effectively buffer the strain and maintain structural integrity but also allow facile and reversible transport of electrons and Na^(+)uptake for electrode materials during sodiation/desodiation processes,resulting in increased reaction kinetics and diffusion of sodium ions,conferring many benefits to the functionality of conversion-type electrode materials.As a representative material,Ni-CoSe_(2) with such structural engineering shows a reversible capacity of 515 mAh g^(−1)at 0.1 A g^(−1)and a stable capacity of 416 mAh g^(−1)even at 6.4 A g^(−1);more than 80%of the capacity at 0.1 A g^(−1)could be preserved,so that this strategy holds great promise for designing fast-charging conversion-type anodes in the future.

Influence of dynamic unbalance of wheelsets on the dynamic performance of high-speed cars

With further increasing in running speed of newer high-speed EMUs（electric multiple units）,higher demand for wheelset dynamic balance is required.In order to study the influence of the dynamic unbalance of wheelset on the stability,ride quality,and curving performance for a high-speed car,a detailed dynamic model of a high-speed EMU car is established using the software SIMPACK.The analysis results indicate that the dynamic unbalance of the wheelset significantly influences the dynamic performance of the high-speed car.The increase in dynamic unbalance of the wheelset will decrease the hunting critical speed,worsen the vertical ride quality,and increase the wheelset lateral force,derailment coefficient,and wheel unloading ratio.Therefore,in order to improve the stability,ride quality,and running safety of high-speed car,the values of dynamic unbalance of wheelset should be strictly controlled in manufacturing,and periodically monitored in operation.

Ample dietary fat reduced the risk of primary vesical calculi by inducing macrophages to engulf budding crystals in mice

Although primary vesical calculi is an ancient disease,the mechanism of calculi formation remains unclear.In this study,we established a novel primary vesical calculi model with D,L-choline tartrate in mice.Compared with commonly used melamine and ethylene glycol models,our model was the only approach that induced vesical calculi without causing kidney injury.Previous studies suggest that proteins in the daily diet are the main contributors to the prevention of vesical calculi,yet the effect of fat is overlooked.To assay the relationship of dietary fat with the formation of primary vesical calculi,D,L-choline tartrate-treated mice were fed a high-fat,low-fat,or normal-fat diet.Genetic changes in the mouse bladder were detected with transcriptome analysis.A high-fat diet remarkably reduced the morbidity of primary vesical calculi.Higher fatty acid levels in serum and urine were observed in the high-fat diet group,and more intact epithelia in bladder were observed in the same group compared with the normal-and low-fat diet groups,suggesting the protective effect of fatty acids on bladder epithelia to maintain its normal histological structure.Transcriptome analysis revealed that the macrophage differentiation-related gene C-X-C motif chemokine ligand 14(Cxcl14)was upregulated in the bladders of high-fat diet-fed mice compared with those of normal-or low-fat diet-fed mice,which was consistent with histological observations.The expression of CXCL14 significantly increased in the bladder in the high-fat diet group.CXCL14 enhanced the recruitment of macrophages to the crystal nucleus and induced the transformation of M2 macrophages,which led to phagocytosis of budding crystals and prevented accumulation of calculi.In human bladder epithelia(HCV-29)cells,high fatty acid supplementation significantly increased the expression of CXCL14.Dietary fat is essential for the maintenance of physiological functions of the bladder and for the prevention of primary vesical calculi,which provides new ideas for the reduction of morbidity of primary vesical calculi.