Porous SnO₂ microsphere and its carbon nanotube hybrids: Controllable preparation, structures and electrochemical performances as anode materials

To improve the electrochemical performance of SnO2-based electrode materials, a simple and efficient method was developed for constructing porous SnO2 microsphere (p-SnO2 MS) and its carbon nanotube hybrids (p-SnO2 MS/CNTs), for the first time, by only changing solvent kinds under microwave-radiation conditions. After their microstructures and electrochemical properties were investigated, it is noted to find that the proposed p-SnO2 MS assembled by nano plates is mainly composed of rutile phase with a little orthorhombic phase. Among all single SnO2 materials with different morphologies, p-SnO2 MS displays a charge capacity of 860.59 mAhg(-1) after 50 cycles, and a charge capacity of 593.37 mAhg(-1) at the current density of 4.0 Ag-1. Once hybridized with CNTs, the corresponding charge capacity of p-SnO2 MS/CNTs would improve to 926.58 mAhg(-1) and 625.50 mAhg(-1) respectively under the same conditions. Importantly, p-SnO2 MS/CNTs could deliver quite a stable charge capacity of 478.53 mAhg(-1) after 600 cycles at 1.0 Ag-1 in Li/p-SnO2 MS/CNTs half cells and a high specific capacity of 738.03 mAhg(-1) after 100 cycles in p-SnO2 MS/CNTs/LiNi0.5Co0.2Mn0.3O2 full cells. The relationship between micro-structure and improved electrochemical performance is investigated in detail for both p-SnO2 MS and p-SnO2 MS/CNTs. This work will offer a promising insight into constructing some practical anode materials with improved lithium storage performances. (C) 2021 Elsevier Ltd. All rights reserved.