With the rapid iteration of portable electronics and electric vehicles, developing high-capacity batteries with ultra-fast charging capability has become a holy grail. Here we report rechargeable aluminum-ion batteries capable of reaching a high specific capacity of 200 mAh g−1. When liquid metal is further used to lower the energy barrier from the anode, fastest charging rate of 104 C (duration of 0.35 s to reach a full capacity) and 500% more specific capacity under high-rate conditions are achieved. Phase boundaries from the active anode are believed to encourage a high-flux charge transfer through the electric double layers. As a result, cationic layers inside the electric double layers responded with a swift change in molecular conformation, but anionic layers adopted a polymer-like configuration to facilitate the change in composition.
1 February 2013 in Computational Materials Science
In this paper, micromechanical modelling and simulation were performed for unidirectional fibre reinforced composites subjected to transverse and in-plane shear by finite element method. Representative volume element consisting of fibre, matrix and interface was established for the simulation, considering random fibre distribution. The two dominant damage mechanisms of fibre reinforced composites, matrix plastic deformation and interfacial debonding were taken into account in the simulation. Periodic boundary conditions were applied to the representative volume elements. The simulation results indicate that the failure behaviour of the composites under transverse shear is dominated by matrix plastic damage, while the in-plane shear damage is initiated by interfacial debonding and then ultimate failure is caused by matrix damage. Fibre distribution is found to have a more significant effect on the failure behaviour of the composites under transverse shear than in-plane shear. The predicted in-plane shear strength and failure strain show reasonable agreement with the experimental results.