MULTIPLE AMBIENT HYDROLYSIS DEPOSITION OF TIN OXIDE INTO NANOPOROUS CARBON AS A STABLE ANODE FOR LITHIUM-ION BATTERIES

摘要

Intense efforts have been devoted to exploring new electrode materials for Li-ion batteries (LIBs) in pursuing higher energy density and better cycling stability. Compared to the conventional graphitic anodes, alloying anodes have attracted much attention due to their high theoretical capacities. Among the alloying anodes, SnO2 is an attractive option due to its high theoretical capacity. The hurdle for SnO2 as an anode has been its rapid capacity fading associated to the large Sn volume expansion (up to 259%) during Li~+ insertion. One promising approach is to encapsulate SnO2 or Sn phases into a conducting conduit to accommodate the volumetric change. Therefore, efforts have been devoted to integrating SnO2 or Sn into porous carbonaceous materials such as mesoporous carbon, graphene4 or carbon nanotubes.5 Herein, we utilize the ambient hydrolysis deposition (AHD) methodology developed in our laboratory for a multiple deposition of SnO2 by pre-adsorbing water in a nanoporous carbon, CMK-3.6 AHD utilizes a sequential water adsorption followed by hydrolysis to deposit controllable amounts of SnO2 inside the pores of CMK-3. We then investigated these tailordesigned materials as anodes for LIBs to address the volume-change challenge for SnO2. A SnO2/carbon composite with an intermediate loading of SnO2 showed great cycling stability for 300 cycles with 573 mAh/g retained at a high current density 200 mA/g.