Abstract

In recent years, sodium-ion batteries (SIBs) have received renewed attention due to the continued rise in lithium prices. SIBs are promising to replace lithium-ion batteries under various application scenarios, such as large-scale energy storage systems and low-speed electric vehicles. As the core of SIBs, electrode materials are the key factor demining the electrochemical performance. Key drawback, including cycle stability, air stability and energy density, are refraining the development of SIBs off-industrialization. For a systematic understanding on the development of SIBs, in this review, we summarized the progress of SIBs from the industrialization viewpoint, including the fabrication methods suitable for large scale production of electrode materials of SIBs, and the optimization strategies to improve electrochemical performance. Finally, we proposed promising directions for future development of electrode materials for SIBs toward industrialization.

Background Introduction:

Lithium-ion batteries (LIBs) are widely used in electric vehicles, electronic devices and grid energy storage. The increased demand for electric vehicles creates a shortage of lithium supply, which is accompanied by a ∼320% price hike of lithium carbonate from 114,370 (Aug. 2021) to 482,626 RMB/ton (Aug. 2022). As well known, the distribution of lithium on the Earth is concentrated in South America. Due to the low concentration of Li+ in the ocean, it is difficult to achieve large-scale lithium extraction from seawater with existing technologies. In contrast, sodium is one of the most abundant elements in the earth's crust and is abundant globally, especially in the oceans. Sodium has an absolute price advantage over lithium. Additionally, the expensive transition metal elements used in LIBs cathode materials, such as Co and Ni, can be replaced by cheaper Mn and Fe in Sodium-ion batteries (SIBs). In addition, from the perspective of safety, over-discharge of LIBs can lead to the dissolution of copper current collectors, and corresponding safety hazards. In comparison, the anode current collector of SIBs is aluminum, which can be deeply discharged. For these reasons, SIBs are expected to replace LIBs in areas such as large-scale energy storage systems (ESS) and low-speed electric vehicles.

In this review, we summarized the progress of SIBs from the industrialization viewpoint, including the fabrication methods suitable for large scale production of electrode materials of SIBs, and the optimization strategies to improve electrochemical performance. Finally, we proposed promising directions for future development of electrode materials for SIBs toward industrialization.

Article Highlights:

01. Method for synthesizing electrode materials

Various methods of SIBs electrode materials, such as solvothermal method and sol gel method, are discussed. The author points out that for industrialization, low-cost and mature methods such as co precipitation and high-temperature solid-phase synthesis are more favored.

2. Optimization strategy

Surface coating is used to improve air stability and thermal stability, doping is used to enhance electrochemical performance and air stability, and materials with high cycling stability and low-temperature performance are developed. These optimizations are crucial for advancing the industrial application of sodium ion batteries, with a focus on safety, efficiency, and cost-effectiveness.

3. Prospect and outlook

As a substitute for lithium-ion batteries, the advantages and potential of SIBs lie in the abundance and cost-effectiveness of sodium. In the future, efforts should be made to improve the cycling stability and energy density of electrode materials to enhance the competitiveness of SIBs; Meanwhile, safety, air stability, and low-temperature performance are also necessary conditions for industrialization and large-scale application.

Summary and Outlook:

The shortage of fossil energy and the deterioration of the environment have stimulated the application of renewable energy and electric vehicles, and LIBs stand out from various energy storage devices due to their advantages in energy density. At present, LIBs have occupied the electric vehicle and ESS market. However, due to the shortage of mineable lithium resources, the price of lithium ore has risen rapidly, and the cost of LIBs has increased accordingly. The working principles of SIBs and LIBs are similar. Considering the abundance of sodium, SIBs are of significant advantage on cost comparing with LIBs. Therefore, SIBs are expected to replace LIBs in some fields, such as ESS and low-speed electric vehicles. For the industrialization of SIBs, the requirements of safe, air stabile, cycling stable, and cheap electrode materials are of great significance.

Among various electrode material synthesis methods, as the most promising preparation method for commercialization, the co-precipitation method can directly follow the production process of LIBs, so as to rapidly realize the reliable production of SIBs cathode precursors. This is an excellent solution for the rapidly growing field of SIBs. The solid-phase method can assist achieving excellent electrochemical performance. However, the irregularity of its morphology has become a major challenge preventing its commercialization. Based on the development status of the SIBs industry, it is undeniable that the solid-phase method has the possibility of industrialization. Referring to the previous studies on LIBs, the single crystal cathodes synthesized by the solid-phase method with high tap densities, which are more promising for industrialization.

In this review, we summarized mainstream optimization strategies from different perspectives for industrialization. First of all, for the device to perform well in safety, the cathode with excellent thermal stability and the anode with thin and uniform SEI layer are required. In addition, the air stability and cycle stability of the cathode can be improved by doping or coating with appropriate elements. For the requirements of low cost in the application, the selection of iron-manganese-based cathode materials can meet the requirements, furthermore, biomass anode materials are also effective methods to reduce costs. For low-temperature performance, NASICON-structured polyanionic materials exhibit good low-temperature reversible capacity, and some studies have also focused on improving the low-temperature performance of layered cathodes.

With the development of SIBs industrialization, efforts should be made to simultaneously improve multiple properties of electrode materials to meet the application needs of different scenarios, such as reducing material costs as much as possible while meeting certain cycle stability and energy density, to obtain better competitiveness. However, aspects such as safety, air stability and low temperature performance are necessary conditions for the industrial production and large-scale application of SIBs, and should be the focus of future research.

Article Details:

Progress in electrode materials for the industrialization of sodium-ion batteries

Zhaoxin Guo, Guangdong Qian, Chunying Wang, Ge Zhang, Ruofan Yin, Wei-Di Liu, Rui Liu, Yanan Chen

Article Link:https://doi.org/10.1016/j.pnsc.2022.12.003

Author introduction

Prof. Dr. Yanan Chen from the School of Materials Science and Engineering, Tianjin University. His mainly engages in research on ultra fast preparation of new materials and their application in the field of new energy. In 2016, Professor Yanan Chen and Professor Liangbing Hu first proposed the concept of high-temperature thermal shock and pioneered the emerging research field of ultra fast synthesis of nanomaterials based on the concept of high-temperature thermal shock. Professor Chen published over 70 research papers as the first/corresponding author (including co authors) in top journals such as Nature Sustainability, Nature Comm. (2), JACS (2), Adv. Material. (4), Angew. Chem., NSR, Materials Today (2), Nano Letters (3), ACS Nano, AEM (12), AFM (2), and multiple papers have been selected as highly cited papers. Authorized more than 10 national invention patents and US invention patents, with multiple patent conversions (conversion amount of 4 million). Undertake/participate in major research projects of the National Natural Science Foundation, key research and development programs of the Ministry of Science and Technology, and national science and technology funds. Served as an expert reviewer for the National Natural Science Foundation of China, Swiss National Science Foundation, China Association for Science and Technology Youth Support Program, Science and Technology Awards, and Ministry of Industry and Information Technology Innovation and Entrepreneurship Competition. Served as a reviewer for various internationally renowned academic journals, such as Chemical Reviews, Nature Sustainability, Nature Comm., Science Advances, Matter, Adv. Material, etc.