MoS2–CoS2 synergistic nanoarchitecture-based hollow microspheres for long-life thermal batteries

Abstract

CoS2 is considered as a substitute cathode material for FeS2 in long-life thermal batteries due to its higher thermal stability. However, the CoS2 nanocrystals synthesized by hydrothermal method suffer from serious agglomeration and high crystal defects, which limit their specific capacity and thermal stability. Here, we successfully synthesized a MoS2–CoS2 synergistic nanoarchitecture-based hollow microsphere through a facile one-pot hydrothermal route. A three-stage growth mechanism of MoS2–CoS2 microsphere during the evolution process is revealed. The agglomeration problems are solved and the electrochemical properties are improved due to the porous loose structure as well as the synergistic effect of CoS2 and MoS2. As a result, MoS2–CoS2 cathode exhibits a long discharge time of 4800 s and a large specific capacity of 333.33 mAh g−1 at a current density of 50 mA cm−2 under a cut-off voltage of 1 V at 500 °C. Moreover, good pulse stability and thermal shock resistance are also achieved. This work provides a promising design strategy for cathode materials with high stability and high capacity to realize long-life thermal batteries.