First Publication of Sodium-Ion Battery Paper in Science

On November 6, a sodium-ion battery research paper titled "Rational design of layered oxide materials for sodium-ion batteries," led by Researcher Hu Yongsheng, founder and chairman of HiNa Battery, was published in the world's top-tier academic journal Science. The study proposes a simple method for predicting the configurations of sodium-ion layered oxides and experimentally confirms its effectiveness, providing theoretical guidance for the design and preparation of low-cost, high-performance sodium-ion battery layered oxide cathode materials. It is reported that this marks the first time in over a century since Science's inception that it has published an article in the field of sodium-ion batteries. This not only demonstrates the importance placed by the mainstream international scientific community on this technological breakthrough but also corroborates that China's cutting-edge sodium-ion battery technology is on par with the world's most advanced levels. Other contributors to the research include Associate Researcher Lu Yaxiang from the Institute of Physics of the Chinese Academy of Sciences, Professor Claude Delmas from the University of Bordeaux in France, and Professor Marnix Wagemaker from the Delft University of Technology in the Netherlands (co-corresponding authors).

Development Background

In recent years, with the rapid development of the global chemical battery market and increasing attention to environmental issues, secondary batteries (also known as rechargeable batteries or accumulators), a novel energy storage technology capable of converting electrical energy into chemical energy, have garnered widespread attention in the new energy revolution. Among them, lithium-ion batteries have become the "undisputed leader," occupying 80% of the global electrochemical energy storage market. However, due to the scarcity of lithium resources and their relatively high cost, the industry faces a developmental "ceiling." Sodium-ion batteries, with their abundant resource reserves and low cost, have emerged as an excellent complementary solution. Nevertheless, the performance of sodium-ion batteries is constrained by available electrode materials, particularly cathode materials dominated by layered oxides.

Since 1980, lithium-ion layered oxides (LiMO₂) have been the primary cathode materials for lithium-ion batteries, with a stacking configuration of the O-type (Octahedral). In contrast, sodium-ion layered oxides (NaₓMO₂) exhibit both O and P (Prismatic) configurations, with the two most common structures being O3 and P2 (the numbers represent the number of stacking layers in the smallest repeating unit of oxygen). These two types of layered oxides each have advantages when used as cathode materials for sodium-ion batteries. However, current technical methods can only physically characterize synthesized materials to determine their specific configurations and cannot directly predict their stacking structures. This significantly hinders the performance design of layered oxide cathode materials and the discovery of new cathode materials.

Research Progress

Generally, O3-phase cathode materials have a higher initial Na content, enabling the extraction of more sodium ions and offering higher capacity. They are suitable for applications such as low-speed electric vehicles and large-scale energy storage. P2-phase cathode materials have larger Na layer spacing, which enhances sodium-ion transport rates and maintains the integrity of the layered structure, providing excellent rate performance and cycle performance. They are more advantageous in fast-charging scenarios such as charging stations, frequency regulation, and data centers. In practical industrial product development, if material configurations can be designed in advance, it would allow for precise adaptation and the creation of sodium-ion battery chemical systems with optimal structures, greatly improving research and development efficiency.

The research team led by Hu Yongsheng from the Institute of Physics of the Chinese Academy of Sciences and HiNa Battery is one of the earliest teams globally to focus on this field. In 2016, Dr. Qi Xingguo (now Manager of the Materials Department at HiNa Battery) from the Institute of Physics of the Chinese Academy of Sciences innovatively introduced the concept of "equivalent radius" (equivalent radius, or weighted radius, is calculated by multiplying the radius of a transition metal by its content) to predict stacking structures, providing the initial思路 for this research topic.

In subsequent studies, while summarizing the structural parameters of different series of layered oxides, Hu Yongsheng's team discovered a critical ratio of 1.62 between the Na layer spacing (d(O-Na-O)) and the M layer spacing (d(O-M-O)) for O3 and P2 structure materials. Ratios higher than 1.62 typically form the P2 phase, while those lower than 1.62 tend to form the O3 phase. Increasing the sodium content yields the O3 phase; conversely, reducing the sodium content yields the P2 phase.

Cationic Potential and Its Application in Sodium-Ion Layered Oxides (Data Source)

Based on this, the researchers in this work introduced "cationic potential" to represent the degree of cation electron density and its polarizability, capturing the key interactions in layered materials and making it possible to predict stacking structures. By rationally designing and preparing layered electrode materials with improved performance, they demonstrated that the stacking structure determines material properties, providing an effective solution for the design of alkali metal layered oxides.

Industry experts indicate that this research reveals the competitive relationship between O3-type and P2-type structures in sodium-ion layered oxides, proposes a simple method for predicting stacking structures, optimizes the manufacturing process of sodium-ion batteries, and provides precise guidance for further enhancing the energy storage characteristics of sodium-ion battery systems.

Industrialization Progress

Researcher Hu Yongsheng from the Institute of Physics of the Chinese Academy of Sciences, founder and chairman of HiNa Battery, as one of the main research members of this work, has over a decade of research and development experience in the field of sodium-ion batteries. He has also provided extensive industrialization technical insights and application platforms for the commercial transformation of this technology. HiNa Battery, founded by him, achieved large-scale mass production of sodium-ion batteries within just three years of its establishment, with a monthly production capacity exceeding 300,000 cells. The company holds dozens of core patents related to the composition, structure, manufacturing, and application of sodium-ion battery materials.

Regarding the publication of this research in Science, Researcher Hu Yongsheng stated that over the past few years, the teams from the Institute of Physics of the Chinese Academy of Sciences and HiNa Battery have conducted extensive experimental research on the factors influencing the formation of the two configurations of sodium-ion layered oxides and actively explored their application scenarios in sodium-ion batteries. As a high-tech enterprise focused on the research, development, and production of the new-generation energy storage system—sodium-ion batteries—HiNa Battery hopes to engage in exchanges and collaborations with more research institutions and enterprises in the industry. By aligning product development with market demands, the company aims to promote the industrial application of sodium-ion batteries!