Wenjuan Jiang

Advanced amorphous nanoporous stannous oxide composite with carbon nanotubes as anode materials for lithium-ion batteries

An amorphous nanoporous stannous oxide (ANSO) composite with carbon nanotubes (CNTs) electrode material is synthesized by electrodeposition and anodic oxidation methods. The ANSO@CNTs as an anode material for lithium-ion batteries exhibits a highly reversible specific capacity, stable cycling ability and good rate capabilities. The first discharge capacity is as high as 1895.3 mA h g−1 with a reversible capacity of 1608.2 mA h g−1 at a current density of 100 mA g−1. Furthermore, an electrochemical performance with a highly reversible capacity and enhanced rate capability can be found due to the highly uniform distribution and superior electrochemical and mechanical performances of the CNTs. The preparation approach for the ANSO@CNTs anode material reported in this paper may be applied to large-scale production of anode materials for high performance lithium-ion batteries.

Mechanical properties of Li-Sn alloys for Li-ion battery anodes: A first-principles perspective

Fracture and pulverization induced by large stress during charging and discharging may lead to the loss of electrical contact and capacity fading in Sn anode materials. A good understanding of mechanical properties is necessary for their optimal design under different lithiation states. On the basis of first-principles calculations, we investigate the stress-strain relationships of Li–Sn alloys under tension. The results show that the ideal tensile strengths of Li–Sn alloys vary as a function of Li concentration, and with the increase of Li+ concentration, the lowest tensile strength decreases from 4.51 GPa (Sn) to 1.27 GPa (Li7Sn2). This implies that lithiation weakens the fracture resistance of Li–Sn alloys.

A coupled electrochemical–thermal–mechanical model for spiral-wound Li-ion batteries

In order to clarify the interaction of electrochemistry, thermal and diffusion-induced stress, in this work, we present a coupled electrochemical–thermal–mechanical model for spiral-wound Li batteries by coupling the mass, charge, energy and mechanics conservations as well as the electrochemical kinetics. A series of temperatures and Li concentration parameters on the reaction rate and Li+ transport are employed in this model. The results show that this model is validated for both the electrochemical performances and thermal behaviors at a constant discharge current by finite element simulation. Furthermore, the heat generation of three thermal sources and stress analysis are also discussed. This work is helpful to the battery structural design and battery thermal management.