Search

Semiconductor-based composites are potential anodes for Li-ion batteries, owing to their high theoretical capacity and low cost. However, low stability induced by large volumetric change in cycling restricts the applications of such composites. Here, a hierarchical SnO2@Ni6MnO8 composite comprising Ni6MnO8 nanoflakes growing on the surface of a three-dimensional (3D) SnO2 is developed by a hydrothermal synthesis method, achieving good electrochemical performance as a Li-ion battery anode. The composite provides spaces to buffer volume expansion, its hierarchical profile benefits the fast transport of Li+ ions and electrons, and the Ni6MnO8 coating on SnO2 improves conductivity. Compared to SnO2, the Ni6MnO8 coating significantly enhances the discharge capacity and stability. The SnO2@Ni6MnO8 anode displays 1030 mAh g−1 at 0.1 A g−1 and exhibits 800 mAh g−1 under 0.5 A g−1, along with high Coulombic efficiency of 95%. Furthermore, stable rate performance can be achieved, indicating promising applications. [ABSTRACT FROM AUTHOR]

High energy-storage Li-ion battery needs a high-capacity anode. However, current graphite-based anode doesn't meet this requirement, thus developing high performance anode materials is highly needed and significant. Here, we provide a rational engineering of a multi-layered hollow structure combining with surface coating of polyamine (PANI) layer, forming a Co 3 O 4 /NiO@PANI hybrid using for Li-ion battery anode. PANI is able to effectively improve the conductivity of active materials; besides, PANI is flexible, which can prevent the collapse of the structure caused by volume-expansion during charge and discharge. The multi-layered morphology improves the utilization ratio of voids inside the conventional hollow structured materials, which is significant to improve capacity in practical applications. The Co 3 O 4 /NiO@PANI hybrid-based anode shows a capacity of 1049 mAh g−1 along with a Coulombic efficiency of 99.3% after 100 cycles of 0.2 A g−1. Rate-performance of Co 3 O 4 /NiO@PANI exceeds that of the bare Co 3 O 4 /NiO. It is believed that the hierarchical structure combining multi-layered hollow morphology with surface coating of conductive polymer presented here would find broad applications for developing high-performance energy-storage hybrids. [Display omitted] • A novel Co 3 O 4 /NiO@polyamine is developed for Li-ion battery anode. • Polyamine nanorods on Co 3 O 4 /NiO keep robust during cycling. • Co 3 O 4 /NiO@polyamine anode exhibits a high and stable capacity. • A recoverable rate-performance of Co 3 O 4 /NiO@polyamine is achieved. [ABSTRACT FROM AUTHOR]

[Display omitted] • A Ga-Sn liquid alloy-encapsulated microcapsule is developed as self-healing Li-ion battery anode. • The liquid alloy microcapsules are prepared by using an oil-in-water emulsion. • Liquid alloy-encapsulated microcapsules exhibit high capacity and rate-performance. • Promising applications of Ga-Sn liquid alloy-encapsulated microcapsules is achievable. Engineering emerging anodes for lithium-ion batteries is of great significance. Here, we develop a self-healing anode composing of Ga-Sn liquid alloy infilling in a microcapsule. The microcapsules are prepared by using an oil-in-water emulsion. Liquid state of the Ga-Sn alloy in microcapsules is able to reduce structural failure on the basis of a self-healing mechanism during long-term cycling; the voids of microcapsules alleviate volumetric change of Ga-Sn alloy upon charge–discharge; and carbon shell improves the conductivity. The liquid alloy-encapsulated microcapsule anode exhibits a capacity of 711.6 mA h g−1 after 500 cycles and an ultrahigh Coulombic efficiency of 99.9 %. Moreover, the microcapsules present a recoverable rate-performance. Those properties enable the self-healing Ga-Sn liquid alloy-encapsulated microcapsules developed here to have a good potential for practical applications. [ABSTRACT FROM AUTHOR]

• A novel multi-layered SnO 2 @NiMoO 4 composite is developed for Li-ion battery anode. • The dense NiMoO 4 nanosheets on SnO 2 shorten the Li-ion transfer pathways. • SnO 2 @NiMoO 4 anode exhibits a high capacity. • A well-recoverable rate-performance is achieved. [Display omitted] High-performance anodes are highly needed for lithium-ion batteries to achieve high capacity and energy density. Here, a strategy of combining hollow yolk-shell structure and surface modification is reported to improve the capacity of anode. As a demonstrating case study, a nanosheets-coated multiple-layered SnO 2 @NiMoO 4 composite is prepared through a simple hydrothermal method. The results show that the multilayered SnO 2 microspheres and NiMoO 4 nanosheets would exhibit a synergistic effect, which efficiently improves the electrochemical properties of Li-ion battery anode. During the cycling, the hollow multilayered SnO 2 microspheres coated by NiMoO 4 nanosheets maintain a robust structure, and have a long cycle life. The reversible capacity of SnO 2 @NiMoO 4 anode is as high as 1109 mAh g−1 at 400 mA g−1 for 250 cycles, which is competitive to the bare SnO 2 and some other reports, indicating a potential for developing high-performance Li-ion battery systems. [ABSTRACT FROM AUTHOR]

Hierarchical materials have been considered promising for secondary battery electrodes owing to their capability of accommodating volumetric change of active materials and providing short pathways for rapid transportation of ions and electrons. Herein, we present a rod-on-tube composite consisting of cobalt molybdate (CoMoO 4) nanotubes coating with polyaniline (PANI) hydrogel nanorods, which exhibits a high electrochemical performance as Li-ion battery anode. The hierarchical CoMoO 4 @PANI is prepared through in-situ polymerizing PANI nanorods on the CoMoO 4 nanotubes. The rod-on-tube structure could alleviate the volumetric change of CoMoO 4 during lithiation-delithiation, and improve conductivity for electron transfer. When cycling at 0.5 A g-1, the presented CoMoO 4 @PANI anodes exhibit a large capacity of 805 mAh g-1 after 150 cycles along with a Coulombic efficiency of 99%, which are both exceeding those of the pristine CoMoO 4. A well-recoverable rate-performance is achieved. Furthermore, the density of state (DOS) and band gap of the CoMoO 4 @PANI and pristine CoMoO 4 are also investigated by using density functional theory (DFT) calculations. Image 1 • A rod-on-tube CoMoO 4 @hydrogel composite anode is presented. • Rod-on-tube structure enables rapid transportation of ions and electrons. • CoMoO 4 @hydrogel composite exhibits a high electrochemical performance. • Density function theory calculations verify an improved conductivity. [ABSTRACT FROM AUTHOR]