Reduced Graphene Oxide Supported MnO Nanoparticles with Excellent Lithium Storage Performance

Preparation of a Mulberry-like MnO Specimen and Its Lithium Property

A mulberry-like MnO specimen was prepared using a MnCO3 sample under nitrogen (N2) protection at 700 °C (denoted as MnO-700). When the specimen was used in lithium-ion batteries (LIBs) as anode material, the reversible capacity of 702 mAh g−1 was displayed after 120 cycles at a current density 200 mA g−1, and 365 mAh g−1 of discharge capacity was obtained at 1000 mA g−1 at the 200th cycle. Meanwhile, the sample also exhibited an excellent rate capacity (224 mAh g−1 at 2000 mA g−1). The MnO-700 sample displayed a favorable electrochemical performance that may be ascribed to the unique mulberry-like structure of the MnO microparticles, which can provide enough space to satisfy the volume change of the MnO microparticles during lithium cycling, and also lead to more transfer paths for Li+ insertion/extraction during charge/discharge processes.

3D Hierarchical Microballs Constructed by Intertwined MnO@N-doped Carbon Nanofibers towards Superior Lithium-Storage Properties

MnO is a promising high-capacity anode material for lithium-ion batteries (LIBs), but pristine material suffers short cycle life and poor rate capability, thus hindering the practical application. In this work, a new type of porous MnO microballs stringed with N-doped porous carbon (3DHB-MnO@NC) with a well-connected hierarchical three-dimensional network structure was prepared by the facile self-template method. The 3DHB-MnO@NC electrode can effectively promote the ion/electron transfer and buffer the large volume change of electrode during the electrochemical reaction. As the anode for LIBs, the 3DHB-MnO@NC possesses outstanding cycling performance (1247.7 mA h g^-1 after 90 cycles at 200 mA g^-1 ) and good rate capabilities (949.6 mA h g^-1 after 450 cycles at 1000 mA g^-1 ). The facile self-template method of the prepared 3DHB-MnO@NC composite paves a new way for practical applications of MnO in high performance LIBs.

Effect of cobalt alloying on the electrochemical performance of manganese oxide nanoparticles nucleated on multiwalled carbon nanotubes

MnO is an electrically insulating material which limits its usefulness in lithium ion batteries. We demonstrate that the electrochemical performance of MnO can be greatly improved by using oxygen-functional groups created on the outer walls of multiwalled carbon nanotubes (MWCNTs) as nucleation sites for metal oxide nanoparticles. Based on the mass of the active material used in the preparation of electrodes, the composite conversion-reaction anode material Mn_1-x Co _x O/MWCNT with x = 0.2 exhibited the highest reversible specific capacity, 790 and 553 mAhg^-1 at current densities of 40 and 1600 mAg^-1, respectively. This is 3.1 times higher than that of MnO/MWCNT at a charge rate of 1600 mAg^-1. Phase segregation in the [Formula: see text] nanoparticles was not observed for x ≤ 0.15. Capacity retention in x = 0, 0.2, and 1 electrodes showed that the corresponding specific capacities were stabilized at 478, 709 and 602 mAhg^-1 respectively, after 55 cycles at a current density of 400 mAg^-1. As both MnO and CoO exhibit similar theoretical capacities and MnO/MWCNT and CoO/MWCNT anodes both exhibit lower performance than Mn_0.8Co_0.2O/MWCNT, the improved performance of the [Formula: see text] alloy likely arises from beneficial synergistic interactions in the bimetallic system.

Hierarchical porous MnO/graphene composite aerogel as high-performance anode material for lithium ion batteries

MnO/graphene composite anode material with hierarchical pore structure shows high capacity, excellent rate capability and stability.

High Performance Metal Oxide-Graphene Hybrid Nanomaterials Synthesized via Opposite-Polarity Electrosprays

An opposite-polarity electrospray technique is developed to synthesize Mn₃ O₄ -graphene hybrid nanomaterial that shows high specific capacity, fast charging/discharging capability, and long cycle life for lithium storage. The approach offers nanoparticle size control and tunability, morphology control, versatility for the synthesis of different materials and hybrid structures from different precursors, and continuous-flow nanomanufacturing with the potential for full automation.

Conversion Reaction-Based Oxide Nanomaterials for Lithium Ion Battery Anodes

Developing high-energy-density electrodes for lithium ion batteries (LIBs) is of primary importance to meet the challenges in electronics and automobile industries in the near future. Conversion reaction-based transition metal oxides are attractive candidates for LIB anodes because of their high theoretical capacities. This review summarizes recent advances on the development of nanostructured transition metal oxides for use in lithium ion battery anodes based on conversion reactions. The oxide materials covered in this review include oxides of iron, manganese, cobalt, copper, nickel, molybdenum, zinc, ruthenium, chromium, and tungsten, and mixed metal oxides. Various kinds of nanostructured materials including nanowires, nanosheets, hollow structures, porous structures, and oxide/carbon nanocomposites are discussed in terms of their LIB anode applications.

Facile synthesis of MnOx nanoparticles sandwiched between nitrogen-doped carbon plates for lithium ion batteries with stable capacity and high-rate capability

MnO_x nanoparticles sandwiched between nitrogen-doped carbon plates architecture (C/MnO_x/C) has been successfully synthesized via a step-by-step strategy.

Membranes of MnO Beading in Carbon Nanofibers as Flexible Anodes for High-Performance Lithium-Ion Batteries

Freestanding yet flexible membranes of MnO/carbon nanofibers are successfully fabricated through incorporating MnO₂ nanowires into polymer solution by a facile electrospinning technique. During the stabilization and carbonization processes of the as-spun membranes, MnO₂ nanowires are transformed to MnO nanoparticles coincided with a conversion of the polymer from an amorphous state to a graphitic structure of carbon nanofibers. The hybrids consist of isolated MnO nanoparticles beading in the porous carbon and demonstrate superior performance when being used as a binder-free anode for lithium-ion batteries. With an optimized amount of MnO (34.6 wt%), the anode exhibits a reversible capacity of as high as 987.3 mAh g⁻¹ after 150 discharge/charge cycles at 0.1 A g⁻¹, a good rate capability (406.1 mAh g⁻¹ at 3  A g⁻¹) and an excellent cycling performance (655 mAh g⁻¹ over 280 cycles at 0.5 A g⁻¹). Furthermore, the hybrid anode maintains a good electrochemical performance at bending state as a flexible electrode.

Recent advances in graphene and its metal-oxide hybrid nanostructures for lithium-ion batteries

Today, one of the major challenges is to provide green and powerful energy sources for a cleaner environment. Rechargeable lithium-ion batteries (LIBs) are promising candidates for energy storage devices, and have attracted considerable attention due to their high energy density, rapid response, and relatively low self-discharge rate. The performance of LIBs greatly depends on the electrode materials; therefore, attention has been focused on designing a variety of electrode materials. Graphene is a two-dimensional carbon nanostructure, which has a high specific surface area and high electrical conductivity. Thus, various studies have been performed to design graphene-based electrode materials by exploiting these properties. Metal-oxide nanoparticles anchored on graphene surfaces in a hybrid form have been used to increase the efficiency of electrode materials. This review highlights the recent progress in graphene and graphene-based metal-oxide hybrids for use as electrode materials in LIBs. In particular, emphasis has been placed on the synthesis methods, structural properties, and synergetic effects of metal-oxide/graphene hybrids towards producing enhanced electrochemical response. The use of hybrid materials has shown significant improvement in the performance of electrodes.

Integration of MnO@graphene with graphene networks towards Li-ion battery anodes

We have directly integrated MnO@graphene with graphene networks through the thermal decomposition of Mn–oleate complex in an argon atmosphere at high temperatures. The MnO/graphene composites exhibited superior cycling performance.

MnO2 nanoflakes anchored on reduced graphene oxide nanosheets as high performance anode materials for lithium-ion batteries

A MnO₂ nanoflake–reduced graphene oxide (MnO₂–rGO) composite was synthesized by a facile solution method.