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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]

Graphical abstract Highlights • A biomimetic composite cathode is fabricated. • The cathode shows high capacity and good low-temperature performance. • Enhanced electron transfer is confirmed by first-principle modeling. • Highly-stable large capacity battery is achievable. Abstract High capacity and good safety secondary batteries are desired for portable electronics and electric vehicles. Currently, an effective method for simultaneously improving the intrinsically poor conductivity and the low capacity of cathodes remains a challenge. Here we present a biomimetic composite consisting of novel litchi-like LiFePO 4 spheres assembled by 20 nm nanoparticles and reduced graphene oxides (rGO). In particular, this biomimetic cathode provides short electron transfer pathways inside the LiFePO 4 spheres (through the hierarchical structure) and on the surface (by the interconnected rGO scaffold). The composite shows a high capacity of 161 mAh g−1 after 200 cycles, accompanying with a good Coulombic efficiency of about 100%. In addition, the composite retains a capacity of 93 mAh g−1 after cycling for 400 times, and shows a good capacity retention when cycling at −5 °C. [ABSTRACT FROM AUTHOR]

[Display omitted] • A free-standing NiCo 2 O 4 nanowires/ginkgo biloba composite is developed for Li-ion battery anode. • Surface growth on biomass achieves a low interfacial reaction barrier for energy-storage. • Nanowires/ginkgo biloba composite displays high performance at different temperatures. • The developed composite system is applicable for other metal oxide nanomaterials. The low cost and special structure of biomass materials enable them to be applicable for many energy-storage systems. Here, we develop NiCo 2 O 4 nanowires growing on carbonized ginkgo biloba to form free-standing anodes of Li-ion battery. The porous NiCo 2 O 4 nanowires have a high capacity, and they are able to accommodate the expansion of volume in cycling. Low surface reaction barrier of the NiCo 2 O 4 /ginkgo biloba anode is confirmed by galvanostatic intermittent titration technique analysis. The NiCo 2 O 4 /ginkgo biloba anode displays recoverable rate-performance and good stability when cycling at different current densities, which remains 2.6 mAh cm−2 after 350 cycles at room temperature. The Coulombic efficiency is about 99 % under −10 °C at 1 mA cm−2, and the capacity remains 1.28 mAh cm−2 after cycling 200 times. Capacity keeps 1.83 mA cm−2 under 45 °C, exhibiting a good Li-storage performance. The NiCo 2 O 4 /ginkgo biloba anode displays a better cycling performance than NiCo 2 O 4 /nickel foam and NiCo 2 O 4 /carbon cloth. The cost-effective synthesis strategy provides extensible applications for metal oxide/ginkgo biloba-based composites. Growing other binary metal oxides on the carbonized ginkgo biloba is also achievable such as ZnCo 2 O 4 , indicating the developed composite system is promising for preparing other free-standing energy-storage composites. [ABSTRACT FROM AUTHOR]

Among many types of batteries, Li-ion and Li-S batteries have been of great interest because of their high energy density, low self-discharge, and non-memory effect, among other aspects. Emerging applications require batteries with higher performance factors, such as capacity and cycling life, which have motivated many research efforts on constructing high-performance anode and cathode materials. Herein, recent research about cathode materials are particularly focused on. Low electron and ion conductivities and poor electrode stability remain great challenges. Three-dimensional (3D) porous nanostructures commonly exhibit unique properties, such as good Li+ ion diffusion, short electron transfer pathway, robust mechanical strength, and sufficient space for volume change accommodation during charge/discharge, which make them promising for high-performance cathodes in batteries. A comprehensive summary about some cutting-edge investigations of Li-ion and Li-S battery cathodes is presented. As demonstrative examples, LiCoO2, LiMn2O4, LiFePO4, V2O5, and LiNi1−x−yCoxMnyO2 in pristine and modified forms with a 3D porous structure for Li-ion batteries are introduced, with a particular focus on their preparation methods. Additionally, S loaded on 3D scaffolds for Li-S batteries is discussed. In addition, the main challenges and potential directions for next generation cathodes have been indicated, which would be beneficial to researchers and engineers developing high-performance electrodes for advanced secondary batteries. [ABSTRACT FROM AUTHOR]

Cathode materials of Li-ion batteries are important for their overall Li-storage performance. However, current cathodes are still non-ideal with rapid capacity decay and poor stability. Herein, a composite cathode consisting of ternary LiMn 1/3 Co 1/3 Ni 1/3 O 2 particles anchored on reduced graphene oxide sheets is presented, which is prepared through a simple route. The composite cathode exhibits a stable capacity exceeding 120 mAh g−1 after 500 cycles at 0.2 C, along with a high Coulombic efficiency close to 100%, which are obviously improved compared to the pure LiMn 1/3 Co 1/3 Ni 1/3 O 2. In addition, the rate-performance of the composite is also significantly enhanced. We believe that the good electrochemical performance and the general preparation approach are able to enable the composite to find significant applications in high-performance secondary batteries. [ABSTRACT FROM AUTHOR]

Hollow nanostructures have received broad attention for lithium-storage owing to their advantages in accommodating volume-change. However, taking the hollow sphere as an example, the void inside consumes a large volume fraction, resulting in a low material loading. Herein, we present a novel hollow nanosheet using Co 2 SiO 4 as demonstrating example. The Co 2 SiO 4 nanosheets-based anode exhibits a high and stable capacity of 1456 mAh g−1 after 200 cycles at 0.2 A g−1, and an excellent rate-performance after three rounds of cycling. In addition, the dynamic lithiation and delithiation of Co 2 SiO 4 are presented using an in situ transmission electron microscopy technology. Unlabelled Image • A novel hollow Co 2 SiO 4 nanosheet secondary battery anode is presented. • Excellent electrochemical performance with stable capacity and high rate-performance is achievable. • Dynamic lithiation/delithiation is demonstrated using in situ transmission electron microscopy. [ABSTRACT FROM AUTHOR]

Nano-engineering graphene-based composite anodes have motivated broad investigations of the high energy density lithium-ion batteries. Here, a sandwich-like and porous NiCo 2 O 4 @reduced graphene oxide (rGO) nanocomposite was presented. Through an incipient dipping process, the NiCo 2 O 4 precursors attach on the rGO densely, which significantly improves the material loading of the NiCo 2 O 4 @rGO composites. Serving as an anode of the lithium-ion battery, the NiCo 2 O 4 @rGO composites exhibit an unprecedented capacity of 1566 mAh g −1 cycling at a current density of 1000 mA g −1 over 700 times; while a capacity of 886 mAh g −1 at 100 mA g −1 over 100 cycles was achieved upon a NiCo 2 O 4 @rGO//LiCoO 2 full-cell, which indicates a promising potential for high energy density battery applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel coral-like LiMn 2 O 4 cathode is prepared. • Biomimetic LiMn 2 O 4 displays stable energy-storage. • Coral-like nanostructure improves rate-performance. • A stable LiMn 2 O 4 cathode for Li-ion battery is achievable. Lithium-ion battery has been widely used in many fields; however, a good energy–density along with a high working voltage cathode is highly required. Here, a three-dimensional coral-like LiMn 2 O 4 nanostructure is developed by annealing a precursor synthesized through a hydrothermal approach, which displays a stable electrochemical performance as Li-ion battery cathode. The coral-like LiMn 2 O 4 cathode exhibits a capacity exceeds 118 mAh/g when cycling at 0.2C, and a Coulombic efficiency of 98.3%. When cycling at a relatively high rate of 0.5C, the electrochemical performance remains stable after 150 cycles. Moreover, good performances are achieved when cycling at different charge/discharge rates, which are ascribed to the biomimetic coral-like structure facilitates the transport of electrons and ions. The general preparation approach and the stable performance of the coral-like cathode would find broad applications for developing many other emerging energy-storage materials. [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]