Ultrafine SnO2 nanoparticles encapsulated in ordered mesoporous carbon framework for Li-ion battery anodes

Titanicone-derived TiO2 quantum dot@carbon encapsulated ZnO nanorod anodes for stable lithium storage

To address the issues of large volume expansion and low electrical conductivity of ZnO anode nanomaterials during lithium ion battery operation, herein we engineered a rod-like ZnO anode with robust and conductive TiO2 quantum dot (QD)@carbon coating derived from molecular layer deposited titanicone, in which the TiO2 QDs are well confined inside the carbon layer. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) confirm the formation of TiO2 QDs and carbonization of fumaric acid in hybrid films after annealing in H2 atmosphere at 700 °C. Benefiting from a unique protective layer design, the prepared TiO2 QD@carbon@ZnO nanorod (NR) anodes display outstanding cycling performance with a discharge capacity of 1154 mA h g-1 after 100 cycles and 70% capacity retention, along with a high rate capacity of 470 mA h g-1 for 500 cycles at 2 A g-1. Moreover, our work demonstrates an innovative and promising approach toward a robust and conductive metal oxide QD@carbon nanocomposite layer for electrode materials in the future.

Rapid preparation of ultra-fine and well-dispersed SnO2 nanoparticles via a double hydrolysis reaction for lithium storage

An efficient and rapid method is reported for preparing ultra-fine and well-dispersed SnO₂ nanoparticles in a large scale. A simple double hydrolysis reaction between SnO₃^2- and Fe³⁺ ions was masterly used to form a stable colloid system, in which colloidal particles of H₂SnO₃ with negative charges and Fe(OH)₃ with positive charges electrostatically interact with each other and form honeycomb-like "core-shell" units. Through the hydrothermal reaction, the units are easily transformed into SnO₂@FeO(OH) structures. Ultra-fine and well-dispersed SnO₂ particles with less than 6 nm diameter were finally obtained with a high yield by further etching using hydrochloric acid. When used as anode materials for lithium ion batteries, the ultra-fine SnO₂ particles can be easily dispersed into the carbon networks originating from the carbon source of glucose during the hydrothermal reaction. Electrochemical tests confirmed that these ultra-fine SnO₂/C materials were endowed with excellent cyclic stability and C-rate performance. Even at a 1.56 A g^-1 (2C) high current density, the reversible capacity could be maintained at 710 mA h g^-1 after 100 cycles owing to the ultra-fine particle size of SnO₂ and the rich carbon networks.

Nanospace-Confinement Synthesis: Designing High-Energy Anode Materials toward Ultrastable Lithium-Ion Batteries

Exploiting high-capacity and durable electrode materials is pivotal to developing lithium-ion batteries (LIBs) and their applications. Multiscaled nanomaterials have been demonstrated to efficiently couple the advantages of each component on different scales in energy storage fields. However, the precise control of the microstructure remains a great challenge for maximizing their contributions. Nanospace-confined synthesis provides a proactive strategy to build novel multiscaled nanomaterials with controllable internal void space for circumventing the intrinsic volume effects in the charge/discharge process. Herein, the rational design and synthesis of multiscaled high-capacity anode materials are mainly summarized according to their electrochemical mechanisms by choosing 1D channel, 2D interlayer, and 3D space as representative confinement reaction environments. The structure-performance relationships are clarified with the assistance of quantitative calculations, molecular simulations, and so forth. Finally, future potentials and challenges of such a synthesis tactic in designing high-performance electrode materials for next-generation secondary batteries are outlooked.

Comparative study of the implementation of tin and titanium oxide nanoparticles as electrodes materials in Li-ion batteries

Transition metal oxides potentially present higher specific capacities than the current anodes based on carbon, providing an increasing energy density as compared to commercial Li-ion batteries. However, many parameters could influence the performance of the batteries, which depend on the processing of the electrode materials leading to different surface properties, sizes or crystalline phases. In this work a comparative study of tin and titanium oxide nanoparticles synthesized by different methods, undoped or Li doped, used as single components or in mixed ratio, or alternatively forming a composite with graphene oxide have been tested demonstrating an enhancement in capacity with Li doping and better cyclability for mixed phases and composite anodes.

Ordered Mesoporous Carbon Embedded with Cu Nanoparticle Materials for Electrocatalytic Synthesis of Benzyl Methyl Carbonate from Benzyl Alcohol and Carbon Dioxide

We prepared a series of ordered mesoporous carbons embedded with different contents of Cu nanoparticles (Cu/OMC-X) and applied them to electrocatalytic synthesis of benzyl methyl carbonate. The materials were characterized by many measurements, which showed that Cu/OMC-X materials maintain highly ordered mesoporous structures with high surface area and highly dispersed Cu nanoparticles. As expected, the materials exhibit good electrocatalytic performance. The optimal yield of benzyl methyl carbonate reaches 69.7% on Cu/OMC-3.

Facile synthesis of SnO2@carbon nanocomposites for lithium-ion batteries

SnO₂@C nanocomposite nanostructure approach is demonstrated, which confers shielding for volume expansion because of carbon. The SnO₂@C nanocomposite anode exhibits superior cycling stability and rate capability due to the stable electrode structure.

Decoration of mesoporous carbon electrodes with tin oxide to boost their supercapacitive performance

A unique material comprising mesoporous carbon decorated with tin oxide was synthesised by facile incipient wetness impregnation for enhanced charge storage.

Electrostatic Self-assembly of 0D-2D SnO2 Quantum Dots/Ti3C2Tx MXene Hybrids as Anode for Lithium-Ion Batteries

MXenes, a new family of two-dimensional (2D) materials with excellent electronic conductivity and hydrophilicity, have shown distinctive advantages as a highly conductive matrix material for lithium-ion battery anodes. Herein, a facile electrostatic self-assembly of SnO2 quantum dots (QDs) on Ti3C2Tx MXene sheets is proposed. The as-prepared SnO2/MXene hybrids have a unique 0D-2D structure, in which the 0D SnO2 QDs (~ 4.7 nm) are uniformly distributed over 2D Ti3C2Tx MXene sheets with controllable loading amount. The SnO2 QDs serve as a high capacity provider and the "spacer" to prevent the MXene sheets from restacking; the highly conductive Ti3C2Tx MXene can not only provide efficient pathways for fast transport of electrons and Li ions, but also buffer the volume change of SnO2 during lithiation/delithiation by confining SnO2 QDs between the MXene nanosheets. Therefore, the 0D-2D SnO2 QDs/MXene hybrids deliver superior lithium storage properties with high capacity (887.4 mAh g-1 at 50 mA g-1), stable cycle performance (659.8 mAh g-1 at 100 mA g-1 after 100 cycles with a capacity retention of 91%) and excellent rate performance (364 mAh g-1 at 3 A g-1), making it a promising anode material for lithium-ion batteries.