Cobalt oxide modified porous carbon anode enhancing electrochemical performance for Li-ion batteries

A Review of Cobalt-Containing Nanomaterials, Carbon Nanomaterials and Their Composites in Preparation Methods and Application

With the increasing demand for sustainable and green energy, electric energy storage technologies have received enough attention and extensive research. Among them, Li-ion batteries (LIBs) are widely used because of their excellent performance, but in practical applications, the electrochemical performance of electrode materials is not satisfactory. Carbon-based materials with high chemical stability, strong conductivity, high specific surface area, and good capacity retention are traditional anode materials in electrochemical energy storage devices, while cobalt-based nano-materials have been widely used in LIBs anodes because of their high theoretical specific capacity. This paper gives a systematic summary of the state of research of cobalt-containing nanomaterials, carbon nanomaterials, and their composites in LIBs anodes. Moreover, the preparation methods of electrode materials and measures to improve electrochemical performance are also summarized. The electrochemical performance of anode materials can be significantly improved by compounding carbon nanomaterials with cobalt nanomaterials. Composite materials have better electrical conductivity, as well as higher cycle ability and reversibility than single materials, and the synergistic effect between them can explain this phenomenon. In addition, the electrochemical performance of materials can be significantly improved by adjusting the microstructure of materials (especially preparing them into porous structures). Among the different microscopic morphologies of materials, porous structure can provide more positions for chimerism of lithium ions, shorten the diffusion distance between electrons and ions, and thus promote the transfer of lithium ions and the diffusion of electrolytes.

ZrO2 coated Li1.9K0.1ZnTi3O8 as an anode material for high-performance lithium-ion batteries

The Li_1.9K_0.1ZnTi₃O₈@ZrO₂ (1 wt%, 3 wt%, and 5 wt%) anode material was synthesized by doping Li₂ZnTi₃O₈ with potassium and coating ZrO₂, where the ZrO₂ coating layer was prepared by citric acid and zirconium acetate, and the potassium source was KCl. When the added ZrO₂ amount is 3%, the material has the most uniform size, reduced polarization, and reduced charge transfer resistance, and the specific capacity of LKZTO@ZrO₂ (3 w%) was 361.5 mA h g⁻¹ at 200 mA g⁻¹ at the 100th cycle, which is higher than that of LKZTO, of 311.3 mA h g⁻¹. The specific capacities of LKZTO@ZrO₂ (3 w%) at 50, 100, 200, 500, and 1000 mA g⁻¹ after 10 cycles were 424.9, 410.7, 394.1, 337.6 and 270.6 mA h g⁻¹, indicating that LKZTO@ZrO₂ (3 w%) has excellent electrochemical performance.

The Li_1.9K_0.1ZnTi₃O₈@ZrO₂ (1 wt%, 3 wt%, and 5 wt%) anode material was successfully synthesized, where the ZrO₂ coating layer was prepared by citric acid and zirconium acetate, and the potassium source was KCl.

Co3 O4 Polyhedron@MnO2 Nanotube Composite as Anode for High-Performance Lithium-Ion Batteries

In this work, a novel lollipop nanostructure of Co₃ O₄ @MnO₂ composite is prepared as anode material in lithium-ion batteries (LIBs). Cobalt metal-organic framework (ZIF-67) is grown on the open end of MnO₂ nanotubes via a self-assembly process. The obtained ZIF-67@MnO₂ is then converted to Co₃ O₄ @MnO₂ by a simple annealing treatment in air. Scanning electron microscopy, transmission electron microscopy, and X-ray diffraction characterizations indicate that the prepared Co₃ O₄ @MnO₂ takes a lollipop nanostructure with a stick of ≈100 nm in diameter, consisting of MnO₂ nanotube, and a head part of ≈1 µm, consisting of Co₃ O₄ nanoparticles. The charge-discharge tests illustrate that this unique novel configuration endows the resulting Co₃ O₄ @MnO₂ with excellent electrochemical performances, delivering a capacity of 1080 mAh g^-1 at 300 mA g^-1 after 160 cycles, and 696 mAh g^-1 at 1 A g^-1 after 210 cycles, compared with 404 mAh g^-1 and 590 for pure Co₃ O₄ polyhedrons and pure MnO₂ nanotubes at 300 mA g^-1 after 160 cycles, respectively. The lollipop configuration consisting of porous Co₃ O₄ polyhedron and MnO₂ nanotube shows excellent structural stability and facilitates lithium insertion/extraction, leading to excellent cyclic stability and rate capacity of Co₃ O₄ @MnO₂ -based LIBs.

Three-Dimensionally Porous Li-Ion and Li-S Battery Cathodes: A Mini Review for Preparation Methods and Energy-Storage Performance

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 LiNi_1−x−yCo_xMn_yO₂ 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.

Porous Mn-doped cobalt oxide@C nanocomposite: a stable anode material for Li-ion rechargeable batteries

Cobalt oxide is a transition metal oxide, well studied as an electrode material for energy storage applications, especially in supercapacitors and rechargeable batteries, due to its high charge storage ability. However, it suffers from low conductivity, which effectively hampers its long-term stability. In the present work, a simple strategy to enhance the conductivity of cobalt oxide is adopted to achieve stable electrochemical performance by means of carbon coating and Mn doping, via a simple and controlled, urea-assisted glycine-nitrate combustion process. Structural analysis of carbon coated Mn-doped Co₃O₄ (Mn-Co₃O₄@C) confirms the formation of nanoparticles (∼50 nm) with connected morphology, exhibiting spinel structure. The Mn-Co₃O₄@C electrode displays superior electrochemical performance as a Li-ion battery anode, delivering a specific capacity of 1250 mAh g^-1. Mn-Co₃O₄@C demonstrates excellent performance in terms of long-term stability, keeping charge storage ability intact even at high current rates due to the synergistic effects of fast kinetics-provided by enriched electronic conductivity, which allows ions to move freely to active sites and electrons from reaction sites to substrate during redox reactions-and high surface area combined with mesoporous architecture. The fully assembled battery device using Mn-Co₃O₄@C and standard LiCoO₂ electrode shows 90% capacity retention over 100 cycles.

A low-cost and one-step synthesis of a novel hierarchically porous Fe3O4/C composite with exceptional porosity and superior Li+ storage performance

A novel Fe₃O₄/C composite with a hierarchical pore carbon network has been synthesized simply by one-step pyrolysis synthesis using ferrous gluconate as the precursor, which shows excellent electrochemical properties as an anode material for LIBs.