Xingrui Liu

Highly Flexible Graphene/Mn3O4 Nanocomposite Membrane as Advanced Anodes for Li-Ion Batteries

Advanced electrode design is crucial in the rapid development of flexible energy storage devices for emerging flexible electronics. Herein, we report a rational synthesis of graphene/Mn3O4 nanocomposite membranes with excellent mechanical flexibility and Li-ion storage properties. The strong interaction between the large-area graphene nanosheets and long Mn3O4 nanowires not only enables the membrane to endure various mechanical deformations but also produces a strong synergistic effect of enhanced reaction kinetics by providing enlarged electrode/electrolyte contact area and reduced electron/ion transport resistance. The mechanically robust membrane is explored as a freestanding anode for Li-ion batteries, which delivers a high specific capacity of ∼800 mAh g(-1) based on the total electrode mass, along with superior high-rate capability and excellent cycling stability. A flexible full Li-ion battery is fabricated with excellent electrochemical properties and high flexibility, demonstrating its great potential for high-performance flexible energy storage devices.

Green Synthesis of Hierarchically Porous Carbon Nanotubes as Advanced Materials for High-Efficient Energy Storage

Hierarchically porous carbon nanomaterials with well-defined architecture can afford a promising platform for effectively addressing energy and environmental concerns. Herein, a totally green and straightforward synthesis strategy for the fabrication of hierarchically porous carbon nanotubes (HPCNTs) by a simple carbonization treatment without any assistance of soft/hard templates and activation procedures is demonstrated. A high specific surface area of 1419 m2 g-1 and hierarchical micro-/meso-/macroporosity can be achieved for the HPCNTs. The unique porous architecture enables the HPCNTs serving as excellent electrode/host materials for high-performance supercapacitors and Li-sulfur batteries. The design strategy may pave a new avenue for the rational synthesis of hierarchically porous carbon nanostructures for high-efficient energy storage applications.

Triaxial Nanocables of Conducting Polypyrrole@SnS2@Carbon Nanofiber Enabling Significantly Enhanced Li-Ion Storage

Two-dimensional (2D) SnS2 materials represent a class of high-capacity candidates as anodes of Li-ion batteries (LIBs); however, they are limited by inferior rate and cycling performance. Herein, we demonstrate unique triaxial nanocables of conducting polypyrrole@SnS2@carbon nanofiber (PPy@SnS2@CNF) prepared via a facile combination of hydrothermal method and vapor-phase polymerization. The PPy@SnS2@CNF manifests a strong synergistic effect from its hierarchical nanoarchitecture, which provides enlarged electrode/electrolyte contact interfaces, highly electrical conductive pathways, sufficient electrolyte ingress/transport channels, and an intimate mechanical/electrochemical safeguard for fast electrode kinetics and good structural stability. When evaluated as binder-free anodes of LIBs, the ternary nanocomposite delivers an ultrahigh reversible capacity of 1165 mAh g-1 after 100 cycles and outstanding rate/cycling performance (880 mAh g-1 at 2000 mA g-1), which are among the best results of the previously reported SnS2 electrodes. This work may pave a rational avenue of developing 2D materials with hierarchical structures for highly efficient energy-storage systems.

Au/TiO2 Hollow Spheres with Synergistic Effect of Plasmonic Enhancement and Light Scattering for Improved Dye-Sensitized Solar Cells

Au-decorated TiO2 hollow spheres (Au-THS) have been successfully synthesized via a facile one-pot solvothermal method. The Au-THS hybrid features unique hollow structure with a large specific surface area of 120 m2 g-1 and homogeneous decoration of Au nanoparticles, giving rise to enhanced light harvesting and charge generation/separation efficiency. When incorporated into the active layer of dye-sensitized solar cells (DSSCs), an improved power conversion efficiency of 7.3% is obtained, which is increased by 37.7% compared with the controlled P25 DSSC. The underlying mechanism to rationalize the efficiency enhancement can be mainly attributed to the strong synergistic effect of superior light scattering ability of the THS and the plasmonic-enhanced effect rendered by the Au nanoparticles.

Graphene-Boosted, High-Performance Aqueous Zn-Ion Battery

Given their low cost and eco-friendliness, rechargeable Zn-ion batteries (ZIBs) have received increasing attention as a device with great potential for large-scale energy storage. However, the development of ZIBs with high capacities and long lifespans is challenging because of the dendritic growth of Zn and the absence of suitable cathode materials. Herein, we report a novel rechargeable aqueous Zn-ion battery (AZIB) that consist of Zn coated with reduced graphene oxide as the anode and V3O7·H2O/rGO composite as the cathode. The new AZIB exhibits excellent cycle stability with a high capacity retention of 79% after 1000 cycles. Moreover, it can deliver a high power density of 8400 W kg-1 at 77 W h kg-1 and a high energy density of 186 W h kg-1 at 216 W kg-1, and the former is higher than those of previously reported AZIBs. Our work provides a new perspective in developing rechargeable ZIBs and would greatly accelerate the practical applications of rechargeable ZIBs.