Lithium slurry flow cell,a promising device for the future energy storage

Lithium slurry flow cell(LSFC)is a novel energy storage device that combines the concept of both lithium ion batteries(LIBs)and flow batteries(FBs).Although it is hoped to inherit the advantages of both LIBs and FBs,such as high energy density,ease of fabrication,environmental friendly,independent energy and power density,to name but a few.While unfortunately,it still has many challenges to overcome before it becoming the future star in energy storage area.Here in this paper,we briefly recall its history and try to illustrate the main issues that hindering its research as well as application.As a typical interdisciplinary product,LSFC is definitely a promising candidate for large scale energy storage application,while obviously it still has a long way to go.

Slurry flow characteristics control of 3D printed ceramic core layered structure:Experiment and simulation

Vat photopolymerization 3D printing ceramic technology provides a feasible process for the preparation of complex internal cooling channels for aeroengine single crystal superalloy hollow blades.However,the typical layered structure characteristics of 3D printing ceramic technology led to the anisotropy of ceramic core strength and sintering shrinkage,which greatly affects the performance and accuracy of the complex structure core and requires further research and improvement.Herein,the influence of the thickness of the slurry layer on the flow characteristics of the slurry in the process of the vat photopolymerization 3D printing slurry spreading was systematically studied by the method of simulation and experiment.The simulation results show that the positions of the turbulent zone and maximum velocity zone in the scraper front affect the redistribution of powder particles with different sizes.The layered structure was caused by the redistribution of ceramic particles of different sizes in the slurry layer.By controlling the turbulent flow zone and the maximum velocity zone of the scraper leading edge,the phenomenon of laminar flow can be weakened and the particle redistribution can be improved.With the increase of the thickness of the printing layer,the layered structure appears gradually,and the pores at the interface of the layered structure gradually concentrated into the interfacial pore lines from the uniform distribution,and the crack propagation changes from intergranular micro-crack to interlayer macro-crack.The combination of finite element simulation and experiment,through the slurry flow characteristics to control the layered structure of reductive vat photopolymerization ceramic core 3D printing,the control of crack propagation mode,element distribution and pore evolution of the core was accomplished,which lays a foundation for the performance control of ceramic 3D printing technology.

Experiment and simulation of slurry flow in irregular channels to understand proppant transport in complex fractures

Slurry flow and proppant placement in irregular fractures are crucial to evaluate hydraulic fracturing stimulation but need to be better understood.This study aims to investigate how irregular fracture affects proppant transport and distribution using laboratory experiments and micro-scale numerical models.The unresolved method of the computational fluid dynamics(CFD)and the discrete element method(DEM)considers Saffman lift force,Magnus force,and virtual mass force to accurately capture the frequent interaction between proppant and slickwater.Experimental results validated the reliability of the optimized CFD-DEM model and calibrated primary parameters.The effects of crack height and width,bending angle,and distance between the crack and inlet on particle distribution were studied.The results indicated that the improved numerical method could rationally simulate proppant transport in fractures at a scale factor.The small crack height causes downward and upward flows,which wash proppant to the fracture rear and form isolated proppant dunes.A wider region in the fracture is beneficial to build up a large dune,and the high dune can hinder particle transport into the fracture rear.When the crack is close to the inlet,the primary fracture without proppants will close to hinder gas production.The smaller the bending angle,the smaller the proppant dune.A regression model can precisely predict the dune coverage ratio.The results fundamentally understand how complex fractures and natural cracks affect slurry flow and proppant distribution.

Phenomenological Based Soft Sensor for Online Estimation of Slurry Rheological Properties

This work proposes a soft sensor based on a phenomenological model for online estimation of the density and viscosity of a slurry flowing through a pipe-and-fittings assembly(PFA). The model is developed considering the conservation principle applied to mass and momentum transfer and considering frictional energy losses to include the variables directly affecting slurry properties. A reported proposal for state observers with unknown inputs is used to develop the first block of the observer structure. The second block is constructed with two options for evaluating slurry viscosity, generating two possible estimator structures, which are tested using real data. A comparison between them indicates different uses and capabilities according to available process information.

Y_(2)O_(3) nanosheets as slurry abrasives for chemical-mechanical planarization of copper

Continued reduction in feature dimension in integrated circuits demands high degree of flatness after chemical mechanical polishing.Here we report using new yttrium oxide(Y_(2)O_(3))nanosheets as slurry abrasives for chemical-mechanical planarization(CMP)of copper.Results showed that the global planarization was improved by 30%using a slurry containing Y_(2)O_(3) nanosheets in comparison with a standard industrial slurry.During CMP,the two-dimensional square shaped Y_(2)O_(3) nanosheet is believed to induce the low friction,the better rheological performance,and the laminar flow leading to the decrease in the within-wafer-non-uniformity,surface roughness,as well as dishing.The application of the two-dimensional nanosheets as abrasive in CMP would increase the manufacturing yield of integrated circuits.