Microwave-assisted and gram-scale synthesis of ultrathin SnO2 nanosheets with enhanced lithium storage properties

The rational design and fabrication of SnO2-based anode materials could offer a powerful way of effectively alleviating their large volume variation and guaranteeing excellent reaction kinetics for electrochemical lithium storage. Herein, we present an ultrarapid, low-cost, and simple microwave-assisted synthesis of ultrathin SnO2 nanosheets at the gram-scale. The two-dimensional (2D) anisotropic growth depends on microwave dielectric irradiation coupled with surfactant structural direction, and is conducted under low-temperature atmospheric conditions. The ultrathin 2D nanostructure holds a great surface tin atom percentage with high activity, where the electrochemical reaction processes could be facilitated that highly dependent on the surface. Compared with 1D SnO2 nanorods, the ultrathin SnO2 nanosheets exhibit remarkably improved electrochemical lithium storage properties with a high reversible capacity of 757.6 mAh g(-1) at a current density of 200 mA g(-1) up to 40 cycles as well as excellent rate capability and cycling stability. Specifically, the ultrathin 2D nanosheet could significantly reduce ion diffusion paths, thus allowing faster phase transitions, while the sufficient external surface interspace and interior porous configuration could successfully accommodate the huge volume changes. Even more importantly, we develop a promising strategy to produce ultrathin SnO2 nanosheets to tackle their intrinsic problems for commercial applications.

Engineering microtubular SnO2 architecture assembled by interconnected nanosheets for high lithium storage capacity

A self-sacrificing template method is developed to prepare hollow SnO₂ microtubes assembled by interconnected nanosheets, which exhibited excellent lithium storage performance.

One-step synthesis of the nickel foam supported network-like ZnO nanoarchitectures assembled with ultrathin mesoporous nanosheets with improved lithium storage performance

Novel network-like ZnO nanoarchitectures are supported on nickel foam as binder-free anodes for high-performance lithium-ion batteries.

Synthesis of hierarchically porous SnO(2) microspheres and performance evaluation as li-ion battery anode by using different binders

We have prepared nanoporous SnO2 hollow microspheres (HMS) by employing the resorcinol-formaldehyde (RF) gel method. Further, we have investigated the electrochemical property of SnO2-HMS as negative electrode material in rechargeable Li-ion batteries by employing three different binders-polyvinylidene difluoride (PVDF), Na salt of carboxy methyl cellulose (Na-CMC), and Na-alginate. At 1C rate, SnO2 electrode with Na-alginate binder exhibits discharge capacity of 800 mA h g(-1), higher than when Na-CMC (605 mA h g(-1)) and PVDF (571 mA h g(-1)) are used as binders. After 50 cycles, observed discharge capacities were 725 mA h g(-1), 495 mA h g(-1), and 47 mA h g(-1), respectively, for electrodes with Na-alginate, Na-CMC, and PVDF binders that amounts to a capacity retention of 92%, 82%, and 8% . Electrochemical impedance spectroscopy (EIS) results confirm that the SnO2 electrode with Na-alginate as binder had much lower charge transfer resistance than the electrode with Na-CMC and PVDF binders. The superior electrochemical property of the SnO2 electrode containing Na-alginate can be attributed to the cumulative effects arising from integration of nanoarchitecture with a suitable binder; the hierarchical porous structure would accommodate large volume changes during the Li interaclation-deintercalation process, and the Na-alginate binder provides a stronger adhesion betweeen electrode film and current collector.

A mild route to mesoporous Mo2C-C hybrid nanospheres for high performance lithium-ion batteries

In this work, we have developed a mild route to fabricate typically mesoporous Mo2C-C hybrid nanospheres based on a solvothermal synthesis and reduction-carbonization process. This work opens a low-temperature route to synthesize valuable carbides. The resultant Mo2C-C hybrid, for the first time, is used as an anode material in lithium ion batteries (LIBs). Compared with bulk Mo2C, the Mo2C-C hybrid exhibits much better electrochemical performance. Remarkably, the hybrid electrode can deliver a specific capacity of over 670 mA h g(-1) after 50 cycles at 100 mA g(-1), which is much higher than that of the bulk material (113 mA h g(-1)). Even cycled at a high current density of 1000 mA g(-1), high capacities of around 400-470 mA h g(-1) can still be retained for the Mo2C-C hybrid. It might benefit from the synergistic effect of the nanohybridization, effectively relieving the volume change during the repeated lithium insertion-extraction reactions and maintaining the integrity of the electrical connections. It is expected that the present synthesis strategy for the Mo2C-C hybrid can be extended to other nanostructured carbides with good energy storage performance.

Influence of the diffusion-layer thickness during electrodeposition on the synthesis of nano core/shell Sn–O–C composite as an anode of lithium secondary batteries

Electrodeposition of nano core/shell Sn–O–C composite anodes for lithium secondary batteries and improvement of cycle performances by a simple agitation technique.

In situ growth of hierarchical SnO(2) nanosheet arrays on 3D macroporous substrates as high-performance electrodes

Finding out how to overcome the self-aggregation of nanostructured electrode materials is a very important issue in lithium-ion battery technology. Herein, by an in situ construction strategy, hierarchical SnO2 nanosheet architectures have been fabricated on a three-dimensional macroporous substrate, and thus the aggregation of the SnO2 nanosheets was effectively prevented. The as-prepared hierarchical SnO2 nanoarchitectures on the nickel foam can be directly used as an integrated anode for lithium-ion batteries without the addition of other ancillary materials such as carbon black or binder. In view of their apparent advantages, such as high electroactive surface area, ultrathin sheet, robust mechanical strength, shorter ion and electron transport path, and the specific macroporous structure, the hierarchical SnO2 nanosheets exhibit excellent lithium-storage performance. Our present growth approach offers a new technique for the design and synthesis of metal oxide hierarchical nanoarrays that are promising for electrochemical energy-storage electrodes without carbon black and binder.