Influence of surfactants on the microstructure and electrochemical performance of the tin oxide anode in lithium ion batteries

Different SnO2 micro–nano structures are prepared by precipitation using a surfactant-assisted process. The surfactants, such as cetyltriethylammonium bromide (CTAB) or sodium dodecyl benzene sulfonate (SDBS), can change the crystal growth direction and microstructure of SnO2 primary and secondary particles. Larger SnO2 nanosheets were synthesized without surfactant, and micro-fragments composed of small nanospheres or nanocubes were synthesized using CTAB and SDBS. The CTAB-assisted process resulted in smaller primary particles and larger specific surface area and larger pore volume, as a lithium-ion-battery anode that exhibits superior electrochemical performance compared to the other two anodes. Further investigation showed that the concentration of CTAB had a substantial influence on the growth of the crystal face, morphology and size of the SnO2 secondary particles, which influenced the electrochemical performance of the anode. A simple mechanism for the influence of surfactants on SnO2 morphology and size in the precipitation and annealing process is proposed.