Ordered 1D and 3D mesoporous Co3O4 structures: Effect of morphology on Li-ion storage and high rate performance

3D Porous Co3O4/MXene Foam Fabricated via a Sulfur Template Strategy for Enhanced Li/K-Ion Storage

Co₃O₄ is a potential high-capacity anode material for lithium-ion batteries (LIBs) and potassium-ion batteries (PIBs), but the poor electrical conductivity and large volume fluctuations during long-term cycling severely limit its cycle durability and rate capabilities, especially for PIBs with large K-ion size. Here, we propose a sulfur template route to fabricate an integral 3D porous Co₃O₄/MXene (Ti₃C₂T_x) foam using simple vacuum co-filtrating an aqueous dispersion of Co₃O₄, S and MXene followed by calcining to remove the S template. The 3D porous structure can easily accommodate the large volume changes of Co₃O₄ while maintains electrode structural integrity, allowing to realize outstanding long-term cycle stability when tested as anodes for both LIBs (620.4 mA h g^-1 after 1000 cycles at 1 A g^-1) and PIBs (134.1 mA h g^-1 after 1000 cycles at 0.5 A g^-1). The high metallic conductivity of the 3D porous MXene network further facilitates the electron/ion transmission, resulting in an improved rate capability of 390 mA h g^-1 at 13 A g^-1 for LIBs and 125.3 mA h g^-1 at 1 A g^-1 for PIBs. The robust performance of the 3D porous Co₃O₄/MXene foam reflects its perspective as a high-performance anode material for both LIBs and PIBs.

Modern Nanocomposites and Hybrids as Electrode Materials Used in Energy Carriers

Over the past decades, the application of new hybrid materials in energy storage systems has seen significant development. The efforts have been made to improve electrochemical performance, cyclic stability, and cell life. To achieve this, attempts have been made to modify existing electrode materials. This was achieved by using nano-scale materials. A reduction of size enabled an obtainment of changes of conductivity, efficient energy storage and/or conversion (better kinetics), emergence of superparamagnetism, and the enhancement of optical properties, resulting in better electrochemical performance. The design of hybrid heterostructures enabled taking full advantage of each component, synergistic effect, and interaction between components, resulting in better cycle stability and conductivity. Nowadays, nanocomposite has ended up one of the foremost prevalent materials with potential applications in batteries, flexible cells, fuel cells, photovoltaic cells, and photocatalysis. The main goal of this review is to highlight a new progress of different hybrid materials, nanocomposites (also polymeric) used in lithium-ion (LIBs) and sodium-ion (NIBs) cells, solar cells, supercapacitors, and fuel cells and their electrochemical performance.

Facile synthesis of novel tungsten-based hierarchical core-shell composite for ultrahigh volumetric lithium storage

The development of novel high volumetric capacity electrode materials is crucial to the application of lithium-ion batteries (LIBs) in miniaturized consumer electronics. In this work, a novel tungsten-based octahedron (CoWO₄/Co₃O₄) with unique hierarchical core-shell structure is successfully fabricated by simply calcinating a cyanide-metal framework precursor. Benefitting from the heavy element W, the CoWO₄/Co₃O₄ octahedrons show a high mass density of 5.18 g cm^-3. When applied as anode materials for LIBs, the CoWO₄/Co₃O₄ octahedrons exhibit an ultrahigh volumetric capacity (6226 mAh cm^-3 after 350 cycles at 0.4 A g^-1), superior rate capability (3165 mAh cm^-3 at 3.0 A g^-1) and outstanding long-term cycling performance (4703 mAh cm^-3 at 1.0 A g^-1 after 800 cycles). The extraordinary lithium storage performance can be ascribed to the unique hierarchical core-shell structure and the possible synergistic effect between W and Co, which provide more Li⁺ insertion sites and effectively buffer the volume variation during cycling. This work not only provides an ultrahigh volumetric lithium storage anode, but also gives a simple and general strategy for the synthesis of novel anode materials for high volumetric energy density LIBs.

MoS2 Nanoflower-Derived Interconnected CoMoO4 Nanoarchitectures as a Stable and High Rate Performing Anode for Lithium-Ion Battery Applications

In recent years, conversion-based mixed transition-metal oxides have emerged as a potential anode for the next generation lithium-ion batteries because of their high theoretical capacity and high rate performance. Herein, an interconnected cobalt molybdenum oxide (CoMoO₄) nanoarchitecture derived from molybdenum sulfide (MoS₂) nanoflowers is investigated as an anode for lithium-ion batteries. The interconnected CoMoO₄ displayed an excellent discharge capacity of 1100 mA h g^-1 over 100 cycles at a current rate of C/5. Moreover, the material exhibited an enhanced electrochemical stability, high rate performance, and delivered high discharge capacities of 600 and 220 mA h g^-1, respectively, at 5 C and 10 C after 500 cycles. The excellent cycling stability and high rate performance of interconnected CoMoO₄ are credited to its unique architecture and porous morphology. The above characteristics and the synergetic effect between the constituting metal ions not only provided a shorter diffusion path for the lithium-ion conduction but also improved the electronic conductivity and mechanical strength of the anode. The field-emission scanning electron microscopy analysis of the electrochemically cycled electrode revealed good structural integrity of the electrode. Further, the practical feasibility of interconnected CoMoO₄ in the full cell was analyzed by integrating it with the LiNi_0.8Mn_0.1Co_0.1O₂ cathode, which demonstrated excellent cycling stability and high rate performance.

A novel self-assembled-derived 1D MnO2@Co3O4 composite as a high-performance Li-ion storage anode material

Manganese dioxide (MnO₂) is a high-performance anodic material and applied widely in lithium-ion batteries (LIBs).