Lithium-ion batteries (LIBs) with outstanding energy and power density have been extensively investigated in recent years, rendering them the most suitable energy storage technology for application in emerging markets such as electric vehicles and stationary storage. More recently, sodium, one of the most abundant elements on earth, exhibiting similar physicochemical properties as lithium, has been gaining increasing attention for the development of sodium-ion batteries (SIBs) in order to address the concern about Li availability and cost—especially with regard to stationary applications for which size and volume of the battery are of less importance. Compared with traditional intercalation reactions, conversion reaction-based transition metal oxides (TMOs) are prospective anode materials for rechargeable batteries thanks to their low cost and high gravimetric specific capacities. In this review, the recent progress and remaining challenges of conversion reactions for LIBs and SIBs are discussed, covering an overview about the different synthesis methods, morphological characteristics, as well as their electrochemical performance. Potential future research directions and a perspective toward the practical application of TMOs for electrochemical energy storage are also provided.

https://onlinelibrary.wiley.com/doi/epdf/10.1002/aenm.201902485

Transition Metal Oxide Anodes for Electrochemical Energy Storage in Lithium- and Sodium-Ion Batteries

The development of sodium-ion batteries for large-scale applications requires the synthesis of electrode materials with high capacity, high initial Coulombic efficiency (ICE), high rate performance, long cycle life, and low cost. A rational design of freestanding anode materials is reported for sodium-ion batteries, consisting of molybdenum disulfide (MoS2) nanosheets aligned vertically on carbon paper derived from paper towel. The hierarchical structure enables sufficient electrode/electrolyte interaction and fast electron transportation. Meanwhile, the unique architecture can minimize the excessive interface between carbon and electrolyte, enabling high ICE. The as-prepared MoS2@carbon paper composites as freestanding electrodes for sodium-ion batteries can liberate the traditional electrode manufacturing procedure, thereby reducing the cost of sodium-ion batteries. The freestanding MoS2@carbon paper electrode exhibits a high reversible capacity, high ICE, good cycling performance, and excellent rate capability. By exploiting in situ Raman spectroscopy, the reversibility of the phase transition from 2H-MoS2 to 1T-MoS2 is observed during the sodium-ion intercalation/deintercalation process. This work is expected to inspire the development of advanced electrode materials for high-performance sodium-ion batteries.

MoS2 Nanosheets Vertically Aligned on Carbon Paper: A Freestanding Electrode for Highly Reversible Sodium Ion Batteries

The limited resources and uneven distribution of lithium stimulate strong motivation to develop new rechargeable batteries that use alternative charge carriers. Potassium-ion batteries (PIBs) are at the top of the list of alternatives because of the abundant raw materials and relatively high energy density, fast ion transport kinetics in the electrolyte, and low cost. However, several challenges still hinder the development of PIBs, such as low reversible capacity, poor rate performance, and inferior cycling stability. Research on the cathode is currently focused on developing materials with high energy density and cycling stability, mainly including layered transition metal oxides, polyanion compounds, organic compounds, etc. Anodes based on intercalation reactions, conversion reactions, and alloying with potassium are currently under development, and promising results have been published. This review comprehensively summarizes the research effort to date on the electrode material optimization (e.g., crystals, morphology, reaction mechanisms, and interface control), the synthesis methods, and the full cell fabrication for PIBs to enhance the electrochemical potassium storage and provide a platform for further development in this battery system.

Potassium-ion batteries: outlook on present and future technologies

Molybdenum disulfide (MoS2) has been considered to be a promising anode material for sodium ion batteries (SIBs), because of its high capacity and graphene-like layered structure. However, irreversible conversion reaction during the sodiation/desodiation process is a major problem that must be overcome before its practical applications. In this work, MoS2/amorphous carbon (C) microtubes (MTs) composed of heterostructured MoS2/C nanosheets have been developed via a simple template method. The existence of MoS2/C heterointerface plays a key role in achieving high and stable performance by stabilizing the reaction products Mo and sulfide phases, providing fast electronic and Na+ ions diffusion mobility, and alleviating the volume change. MoS2/C MTs exhibit a high reversible specific capacity of 563.5 mA h g–1 at 0.2 A g–1, good rate performance (520.5, 489.4, 452.9, 425.1, and 401.3 mA h g–1 at 0.5, 1.0, 2.0, 5.0, and 10.0 A g–1, respectively), and excellent cycling stability (484.9 mA h g–1 at 2.0 A g–1 aft...

Construction of MoS2/C Hierarchical Tubular Heterostructures for High-Performance Sodium Ion Batteries

Carbon quantum dot micelles tailored hollow carbon anode for fast potassium and sodium storage

As an anode for lithium-ion batteries, metallic bismuth (Bi) can provide a superb volumetric capacity of 3800 mA h cm–3, showing perspective value for application. It is a pity that the severe volu...

Wanwan Hong

Papers

Carbon quantum dot micelles tailored hollow carbon anode for fast potassium and sodium storage

Yolk-Shell-Structured Bismuth@N-Doped Carbon Anode for Lithium-Ion Battery with High Volumetric Capacity.

Heteroatom-doped carbon inlaid with Sb2X3 (X = S, Se) nanodots for high-performance potassium-ion batteries

Nickel Chelate Derived NiS2 Decorated with Bifunctional Carbon: An Efficient Strategy to Promote Sodium Storage Performance

Hierarchical NiS2 Modified with Bifunctional Carbon for Enhanced Potassium-Ion Storage