Fabrication of SnO₂ Asymmetric Membranes for High Performance Lithium Battery Anode

Abstract

Alloy electrode material like tin dioxide (SnO2) possesses much higher specific capacity as compared to commercial graphite anode in lithium ion battery (783 vs 372 mAh g(-1)). However, the huge volume change (260%) of SnO2-based anode during the alloying and dealloying process can cause significant electrode pulverization and rapid capacity loss. Herein we report the synthesis of SnO2 asymmetric membranes via a unique combination of phase inversion and sol-gel chemistry to overcome this big challenge. The SnO2 asymmetric membrane electrode demonstrates a specific capacity of 500 mAh g(-1) based on the overall electrode mass at a current density of 280 mA g(-1) (∼0.5C) with >96% capacity retention after 400 cycles. When the current density is increased from 28 to 560 mA g(-1), its overall capacity is only reduced by 36%. Such an outstanding rate and cycling performance is attributed to the existence of networking porous structure in the membrane that can provide high electrical conductivity, multiple diffusion channels, and free volumes for electrode expansion. The carbonization temperature has a dramatic impact on the electrode performance. Membranes carbonized at 500 °C show an excellent cycling performance, whereas the capacity of the membrane carbonized at 800 °C decreases by 51% in 100 cycles. Such a drastic difference in cycle life is caused by the reduction of small SnO2 NPs (∼3.9 nm) into large metallic tin spheres (∼40 nm) at 800 °C. This is the first original report on using asymmetric membrane structure to stabilize an SnO2-based lithium ion battery anode with an excellent electrochemical performance.

Porous A‐SnO2/rGO Nanocomposite via Annealing Treatment with Stable High‐Capacity as Anode of Lithium‐Ion Battery

“…The cyclic stability of A‐SnO 2 /rGO is much better than that of N–SnO 2 /rGO when the current density enhanced to 1 C (Figure d). After 300 cycles, the specific capacity of A‐SnO 2 /rGO was kept at 414.2 mAh g −1 , while the capacity of N‐SnO 2 /rGO was reduced to 150.6 mAh g −1 at 1 C. At the same time, the A‐SnO 2 /rGO electrode shows an outstanding Coulombic efficiency with an average Coulombic efficiency close to 100% in the cycles either at 0.1 C or 1 C implying its well electron and Li + ion transports …”

Micron‐size Silicon Monoxide Asymmetric Membranes for Highly Stable Lithium Ion Battery Anode

“…The addition of carbon black is necessary to maintain the porous structure after being carbonized at high temperatures, and enhance the overall membrane conductivity. The formation mechanism of asymmetric membranes can be easily understood using a ternary phase diagram, which has been discussed explicitly in our previous studies . To describe it briefly, the homogeneous phase made of solvent (N‐methyl‐2‐pyrrolidone: NMP) and polymer (Polyacrylonitrile: PAN) is separated into two phases (polymer lean and polymer rich) after being immersed into non‐solvent (deionized water), due to the mixing of solvent and non‐solvent, and de‐mixing of polyacrylonitrile from the solvent/non‐solvent (NMP/water) mixture ,.…”

Innovative and Economically Beneficial Use of Corn and Corn Products in Electrochemical Energy Storage Applications

“…Therefore, tremendous effort has been made to explore the fundamental basics of high-capacity and high-energy electrode materials and many strategies have been proposed to conquer the obstacles of boosting energy density of the batteries. − One strategy is to reduce particle size to nanoscale to alleviate mechanical strain. For example, Liu et al found that, during the first lithiation process, the nanoparticles with diameters less than 150 nm undergo volume expansion without fracturing or cracking, suggesting that nanoparticles can tolerate huge volume change .…”