Nanostructured hybrid layered-spinel cathode material synthesized by hydrothermal method for lithium-ion batteries

Achieving ultra-low voltage fading in Co-free Li-rich layered oxides via effortless surface defect engineering

Cobalt (Co)-free lithium (Li)-rich layered oxides (LLOs) have emerged as promising cathode materials for the next generation of Li-ion batteries, attributed to their competitive market positioning and high energy density. Nevertheless, challenges arise from surface oxygen loss due to irreversible anionic redox reactions, leading to severe voltage and capacity decay that hinder the large-scale adoption of LLOs. Herein, we present an innovative, facile, and environmentally friendly hydrothermal approach to induce surface reconstruction of Li1.2Mn0.6Ni0.2O2 material. A multifaceted combination involving the spinel phase, oxygen vacancies, and reduced manganese is orchestrated to alleviate the irreversible oxygen redox and impressively enhance Li-ion diffusion. The modified sample, owing to this surface transition, demonstrates low-strain and low-distortion properties along with a substantial improvement in structural stability, supported by both experimental validations and theoretical studies. As a result, the engineered sample exhibits exceptional capacity retention of 97.12% after 150 cycles at 1C, with an ultra-low voltage decay (0.91 mV cycle-1). Additionally, noteworthy enhancements in initial coulombic efficiency and rate performance are also observed. This straightforward surface defect engineering method offers a pathway to developing "low-strain" LLOs with superior electrochemical performance, thereby laying a solid foundation for future commercial applications.

Simple Glycerol-Assisted and Morphology-Controllable Solvothermal Synthesis of Lithium-Ion Battery-Layered Li1.2Mn0.54Ni0.13Co0.13O2 Cathode Materials

High-performance lithium-rich-layered oxide is regarded as a promising candidate for lithium-ion battery (LIB) cathode materials because of its outstanding high specific capacity. Despite in-depth research over the past decade, there are still a number of serious problems limiting its commercialization. Here, we report a simple morphological design and size-controllable material preparation strategy to enhance the electrochemical performance of LIB cathode materials. We use a simple solvothermal method to obtain a carbonate precursor material with different morphologies by adjusting the solvent ratio of the system, which will be conveniently formed into Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ by calcination. Moreover, further relation between the morphology and electrochemical performance of cathode materials is systematically investigated. The microsphere cathode material with suitable size exhibits superior electrochemical performances among all samples in terms of initial reversible capacity (280.4 mA h g^-1 at 0.1 C) and cycle performance (87.67% retention after 200 cycles at 1 C). Even at 5 C, a high discharge capacity of 150.8 mA h g^-1 can be obtained. In addition, this work provides a feasible and effective approach to controllable synthesis of stable structures and high-performance oxide electrode materials for LIBs.

Preparation of Layered-Spinel Microsphere/Reduced Graphene Oxide Cathode Materials for Ultrafast Charge-Discharge Lithium-Ion Batteries

Although Li-rich layered oxides (LLOs) have the highest capacity of any cathodes used, the rate capability of LLOs falls short of meeting the requirements of electric vehicles and smart grids. Herein, a layered-spinel microsphere/reduced graphene oxide heterostructured cathode (LS@rGO) is prepared in situ. This cathode is composed of a spinel phase, two layered structures, and a small amount of reduced graphene oxide (1.08 wt % of carbon). The assembly delivers a considerable charge capacity (145 mA h g^-1 ) at an ultrahigh charge- discharge rate of 60 C (12 A g^-1 ). The rate capability of LS@rGO is influenced by the introduced spinel phase and rGO. X-ray absorption and X-ray photoelectron spectroscopy data indicate that Cr ions move from octahedral lattice sites to tetrahedral lattice sites, and that Mn ions do not participate in the oxidation reaction during the initial charge process.

Synthesis of a novel tunnel Na0.5K0.1MnO2 composite as a cathode for sodium ion batteries

A novel tunnel Na_0.5K_0.1MnO₂ rod-like composite assembled by two different tunnel structures of Na_0.44MnO₂ and KMn₈O₁₆ is synthesized. When used as cathode of sodium ion batteries, the composite displays outstanding electrochemical performances.

Glucose-assisted combustion synthesis of Li1.2Ni0.13Co0.13Mn0.54O2 cathode materials with superior electrochemical performance for lithium-ion batteries

Lithium-rich layered Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ cathode materials have been successfully fabricated by a glucose-assisted combustion method combined with a calcination treatment.

Dependence of structure and temperature for lithium-rich layered-spinel microspheres cathode material of lithium ion batteries

Homogeneous lithium-rich layered-spinel 0.5Li₂MnO₃·0.5LiMn_1/3Ni_1/3Co_1/3O₂ microspheres (~1 μm) are successfully prepared by a solvothermal method and subsequent high-temperature calcinations process. The effects of temperature on the structure and performance of the as-prepared cathode material are systemically studied by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), galvanostatical charge/discharge and electrochemical impedance spectra. The results show that a spinel Li₄Mn₅O₁₂ component can be controllably introduced into the lithium-rich layered material at 750°C. Besides, it has been found that the obtained layered-spinel cathode material represents excellent electrochemical characteristics. For example, it can deliver a high initial discharge capacity of 289.6 mAh g⁻¹ between 2.0 V and 4.6 V at a rate of 0.1 C at room temperature, and a discharge capacity of 144.9 mAh g⁻¹ at 5 C and 122.8 mAh g⁻¹ even at 10 C. In addition, the retention of the capacity is still as high as 88% after 200 cycles, while only 79.9% for the single-phase layered material. The excellent electrochemical performance of the as-prepared cathode material can probably be attributed to the hybrid structures combining a fast Li-ion diffusion rate of 3D spinel Li₄Mn₅O₁₂ phase and a high capacity of the layered Li-Mn-Ni-Co-O component.

Template GNL-assisted synthesis of porous Li1.2Mn0.534Ni0.133Co0.133O2: towards high performance cathodes for lithium ion batteries

A high performance cathode of porous Li_1.2Mn_0.534Ni_0.133Co_0.133O₂ for lithium ion batteries synthesized by a GNL-template.

Click-based porous inorganic–organic hybrid material (PHM) containing cyclophosphazene unit and their application in carbon dioxide capture

A high surface area porous hybrid material was synthesized by one-step click chemistry, which captures 1.83 mmol g⁻¹ CO₂ at 273 K.