dc.description.abstract | Rechargeable lithium-ion batteries have attracted considerable attention over the previous two decades for a wide variety of applications such as electric vehicles, smart electricity grids, and portable energy devices. However, today′s lithium-ion batteries lack the higher capacity, stable operation capabilities, and longer lifetime required in transportation applications. In this regard, alternative anode materials, including, SnS2 and Cu2ZnSnS4 have received intensive attention because they deliver ultrahigh theoretical capacity. However, insufficient conductivity, poor low-temperature performance, and as well as volume expansion during cycling lead to poor electrochemical reversibility and cycling stability.
To address the insufficient conductivity, poor low-temperature performance, and mitigate the capacity degradation of SnS2 and Cu2ZnSnS4 materials in lithium–ion storage, morphology (e.g., nanosheet and nanowalls structures), hierarchical configuration, and surface properties of materials need to be developed.
In this regard, we demonstrated a synthesis and the importance of conductive electrode supports as integrated electrodes for anode materials in lithium-ion storage. We directly synthesize SnS2 nanosheet anode materials on various conductive supports, including nonporous planar molybdenum foils, macroporous carbon cloth as well as 3D hierarchical carbon nanotube-carbon cloth composites. Our findings reveal that the SnS2 nanosheet grown on 3D hierarchical carbon nanotube-carbon cloth composites (SnS2-CNT-CC) shows superior capacity retention and cycle stability, compared to that on planar molybdenum (Mo) sheets and carbon cloth. The SnS2-CNT-CC electrode outperforms the other electrode configurations in the cyclic performance and rate capability due to the multi-electron pathway and high surface area derived from 3D hierarchical CNT-CC electrode support.
Similarly, copper zinc tin sulfide (Cu2ZnSnS4, CZTS) thin-film were prepared to study the electrochemical activities under low-temperature (−10 °C ) and the effects of electrolyte on the electrochemical performance. Our results reveal that the quaternary CZTS synthesized by a simple hydrothermal method shows a higher reversible capacity of 475 mAh g−1 after 200 cycles at −10 °C with the EC/DEC/DMC-based electrolyte in the comparison with the graphite electrode (110 mAh g−1 after 100 cycles at −10 °C). The depth-profiling XPS results of the CZTS anode reveal that a solid electrolyte interphase (SEI) layer with less carbon content is formed in the EC/DEC/DMC-based electrolyte likely associated with the interfacial stability at low temperature. The enhanced cycling performance of CZTS could be attributed to its improved interfacial stability and Li+ diffusion kinetics, along with the formation of interconnected active material architecture at low temperatures. | en_US |