Synergetic Contributions from the Components of Flexible 3D Structured C/Ag/ZnO/CC Anode Materials for Lithium-Ion Batteries

Low electronic conductivity and large volume changes during the(de)lithiation process are the two main challenges for ZnO anode materials used for lithium-ion batteries(LIB).Here,a free-standing,flexible,and binder-free LIB electrode composed of ZnO nanorods and carbon cloth(CC)is fabricated.This is then decorated with Ag nanoparticles and finally coated by an amorphous carbon layer to form the hybrid electrode:(C@(Ag&ZnO)).The voids among the nanorods are sufficient to accommodate the volume expansion of the ZnO while the flexible CC,which acts as the current collector,relieves the volume change-induced stress.The Ag nanoparticles are effective in improving the conductivity.This composite electrode shows excellent LIB performance with a stable long cycling life over 500 cycles with a reversible capacity of 1093 mAh g^(-1)at a current density of 200 mA g^(-1).It also shows good rate performance with reversible capacity of 517 mAh g^(-1)under a high-current density of 5000 mA g^(-1).In situ Raman spectroscopy is conducted to investigate the contributions of the amorphous carbon layer to the capacity of the whole electrode and the synergy between the CC and ZnO nanorods.

Analysis of piezoelectric semiconductor fibers under gradient temperature changes

Piezoelectric semiconductors(PSs)possess both semiconducting properties and piezoelectric coupling effects,making them optimal building blocks for semiconductor devices.PS fiber-like structures have wide applications in multi-functional semiconductor devices.In this paper,a one-dimensional(1D)theoretical model is established to describe the piezotronic responses of a PS fiber under gradient temperature changes.The theoretical model aims to explain the mechanism behind the resistance change caused by such gradient temperature changes.Numerical results demonstrate that a gradient temperature change significantly affects the physical fields within the PS fiber,and can induce changes in its surface resistance.It provides important theoretical guidance on the development of piezotronic devices that are sensitive to temperature effects.

Analysis of Piezoelectric Semiconductor Structures Considering Both Physical and Geometric Nonlinearities

Piezoelectric semiconductors(PSs),such as ZnO and GaN,known as the third-generation semiconductors,have promising applications in electronic and optoelectronic devices due to the coexistence and interaction of piezoelectricity and semiconductor properties.Theoretical modeling of PS structures under external loads,such as thermal and mechanical loads,plays a crucial role in the design of PS devices.In this work,we propose a nonlinear fully coupling theoretical model and investigate the multi-field coupling behaviors of PS structures and PN junctions under thermal and mechanical loads,considering physical and geometric nonlinearities.The electromechanical and semiconducting behaviors of a PS rod-like structure with flexural deformations under different combinations of temperature changes and mechanical loads are evaluated.The tuning effect of temperature changes and mechanical loads on multi-field coupling behaviors of PSs is revealed.The current–voltage characteristics of PS PN junctions are studied under different combinations of temperature changes and mechanical loads.The obtained results are helpful for the development of novel PS devices.