Advanced Nanostructured Anode Materials for Sodium‐Ion Batteries

Abstract

Sodium-ion batteries (NIBs), due to the advantages of low cost and relatively high safety, have attracted widespread attention all over the world, making them a promising candidate for large-scale energy storage systems. However, the inherent lower energy density to lithium-ion batteries is the issue that should be further investigated and optimized. Toward the grid-level energy storage applications, designing and discovering appropriate anode materials for NIBs are of great concern. Although many efforts on the improvements and innovations are achieved, several challenges still limit the current requirements of the large-scale application, including low energy/power densities, moderate cycle performance, and the low initial Coulombic efficiency. Advanced nanostructured strategies for anode materials can significantly improve ion or electron transport kinetic performance enhancing the electrochemical properties of battery systems. Herein, this Review intends to provide a comprehensive summary on the progress of nanostructured anode materials for NIBs, where representative examples and corresponding storage mechanisms are discussed. Meanwhile, the potential directions to obtain high-performance anode materials of NIBs are also proposed, which provide references for the further development of advanced anode materials for NIBs.

Recent Progress in Iron‐Based Electrode Materials for Grid‐Scale Sodium‐Ion Batteries

“…Due to the large abundance and low cost of sodium resources and similar chemical/electrochemical properties to established lithium‐ion batteries (LIBs), room temperature sodium‐ion batteries (SIBs) emerge as a potential technology for grid‐scale energy storage . A large number of materials, such as transition metal oxides, phosphates, ferrocyanides, metal alloys, and hard carbon, have been investigated and have shown acceptable electrochemical performance, and some reviews have summarized recent developments in electrodes for SIBs . However, due to the higher molar weight of the Na element and more positive standard electrochemical potential of Na/Na + (compared to Li/Li + ), SIBs exhibit lower energy densities than LIBs.…”

Flexible Na batteries

“…12,19,27 Carbonaceous materials are considered as the most representative anode materials owing to their abundance and high electrochemical performance, particularly hard carbon materials, which have exhibited capacities over~350 mAh g −1 . 12,19,27 Carbonaceous materials are considered as the most representative anode materials owing to their abundance and high electrochemical performance, particularly hard carbon materials, which have exhibited capacities over~350 mAh g −1 .…”

“…51 Both carbon papers showed good flexibility, so they could be directly used as binder-free and self-standing anodes. 19 Unlike the cathode compounds mentioned above in Section 2.1, Ti-based oxides or their precursors can be obtained from liquid-phase methods, resulting in their homogeneous dispersion in the substrates. During the oxidizing treatment, the surface area of the hard carbon material is effectively decreased, leading to a much denser structure.…”

“…Na 2 Ti 3 O 7 , with an open-layered framework in zigzag layers, showed a high theoretical capacity and a low voltage plateau at~0.3 V vs Na/Na + . 19,25,26 However, they usually suffer from severe volume change upon Na + (de)intercalation and low electrical conductivity. 60, 61 An anode composed of Na 2 Ti 3 O 7 nanowires with lengths of >100 mm and a width of 100-200 nm was grown on a carbon cloth substrate via a hydrothermal method, as shown in Figure 3B.…”

“…During the past decade, various electrode materials have been discovered and investigated for use in Na batteries, as shown in Figure 1B,C, including cathode materials [12][13][14][15] : layered oxides, 16 polyanionic compounds, 17 Prussian blue analogues, 18 sulfur and gas (O 2 and CO 2 ) etc, anodes, 14,19 carbon-based materials, 20,21 titanium-based materials, 22,23 alloy materials, 24 chalcogen-based materials, 19,25,26 organic materials, 19,25,26 Na metal anodes, 27 and so forth. During the past decade, various electrode materials have been discovered and investigated for use in Na batteries, as shown in Figure 1B,C, including cathode materials [12][13][14][15] : layered oxides, 16 polyanionic compounds, 17 Prussian blue analogues, 18 sulfur and gas (O 2 and CO 2 ) etc, anodes, 14,19 carbon-based materials, 20,21 titanium-based materials, 22,23 alloy materials, 24 chalcogen-based materials, 19,25,26 organic materials, 19,25,26 Na metal anodes, 27<...>…”