An analytical p-y curve method based on compressive soil pressure model in sand soil

With the high-quality development of urban buildings,higher requirements are come up with for lateral bearing capacity of laterally loaded piles.Consequently,a more accurate analysis to predict the lateral response of the pile within an allowable displacement is an important issue.However,the current p-y curve methods cannot fully take into account the pile-soil interaction,which will lead to a large calculation difference.In this paper,a new analytical p-y curve is established and a finite difference method for determining the lateral response of pile is proposed,which can consider the separation effect of pile-soil interface and the coefficient of circumferential friction resistance.In particular,an analytical expression is developed to determine the compressive soil pressure by dividing the compressive soil pressure into two parts:initial compressive soil pressure and increment of compressive soil pressure.In addition,the relationship between compressive soil pressure and horizontal displacement of the pile is established based on the reasonable assumption.The correctness of the proposed method is verified through four examples.Based on the verified method,a parametric analysis is also conducted to investigate the influences of factors on lateral response of the pile,including internal friction angle,pile length and elastic modulus of pile.

Unshackling the reversible capacity of SiO_(x)/graphite-based full cells via selective LiF-induced lithiation

Composite Si@SiO_(x)/C anodes with high specific capacity are considered the most promising alternatives to graphite in industrial lithium-ion batteries.However,their cycling stability remains a limiting factor,which originates from the severe volume deformation of silicon-derived species.In this work,the cyclabilities of composite anodes are improved by unshackling the highly reversible lithium storage capabilities from the redundancy capacity of the anode materials.A selective LiF-induced lithiation strategy is proposed based on exploiting interface separation energy differences between LiF and the active materials.An interesting preferential redeposition of LiF is observed at the Si@SiO_(x) particles,which differentiates the otherwise similar lithiation potentials of LiC_(x) and Li_(15)Si_(4),thereby enabling lithium storage in graphite that was previously underused.The resulting full cell exhibits better rate and cycling performances without sacrificing specific capacity.In an ultra-high area capacity full cell(4.9 mA h cm^(-2)),the capacity retention increases markedly from 66.1% to 94.2% after 300 cycles.The selective lithiation strategy developed herein is feasible for practical industrial applications,and importantly,it requires no changes to the existing mature lithium-ion battery manufacturing process.This study offers a new approach for the development of silicon/graphite composite anodes with long cycling lifetimes.