One-step solvothermal synthesis of Sn nanoparticles dispersed in ternary manganese-nickel-cobalt carbonate as superior anode materials for lithium ion batteries

Sn with high theoretical specific capacity has suffered from poor cycling stability due to its huge volume changes during charging/discharging processes. In this work, a novel structure of tin nanoparticles well dispersed in ternary manganese-nickel-cobalt carbonate Mn-0.54 Ni-0.13 Co-0.13 (CO3)(0.8) (MNCCO3) is synthesized using a facile one-step solvothermal process and demonstrates significantly improved electrochemical performance compared to Sn nanoparticles or bare MNCCO3. Additionally, Sn content can be optimized to maximize the battery performance of the composite. When tested as an anode material in lithium ion batteries, the composite with 10 wt.% Sn nanoparticles dispersed in MNCCO3 matrix (10Sn@MNCCO3) demonstrates the best performance, delivering a high initial charge capacity of 929 mAh/g and retains a specific capacity of 657 mAh/g after 50 cycles and 560 mAh/g after 100 cycles at a specific current of 100 mA/g. The charge capacity of 10Sn@MNCCO3 decreases from a value of 991 mAh/g when cycled at 50 mA/g to 64 mAh/g at 2000 mA/g with the increasing specific current. When the specific current returns from 2000 mA/g to 50 mA/g, 10Sn@MNCCO3 retains a high capacity of 791 mAh/g. The improved electrochemical performance can be ascribed to the synergic effect of both components in the composite, in which ternary carbonate MNCCO3 matrix not only provides high practical capacity, but also effectively accommodates the strain of dramatic volume change during long cycling, meanwhile Sn ensures a good electrical contact of the overall electrode due to its high electronic conductivity. (C) 2015 Elsevier Ltd. All rights reserved.