Silicon is considered the most promising candidate for anode material in lithium‐ion batteries due to the high theoretical capacity. Unfortunately, the vast volume change and low electric conductivity have limited the application of silicon anodes. In the silicon anode system, the binders are essential for mechanical and conductive integrity. However, there are few reviews to comprehensively introduce binders from the perspective of factors affecting performance and modification methods, which are crucial to the development of binders. In this review, several key factors that have great impact on binders’ performance are summarized, including molecular weight, interfacial bonding, and molecular structure. Moreover, some commonly used modification methods for binders are also provided to control these influencing factors and obtain the binders with better performance. Finally, to overcome the existing problems and challenges about binders, several possible development directions of binders are suggested.

In this work, a flower-like Nb2Se9 material was obtained by a simple oil-phase-assisted synthesis route and used as an anode in lithium-ion and sodium-ion batteries first. It exhibited a high charge capacity (672.35 mAh g–1 at 100 mA g–1), good cycling stability (596.63 mAh g–1 after 250 cycles at 100 mA g–1), and outstanding rate performance (285 mAh g–1 at 5 A g–1) in lithium-ion batteries. Meanwhile, the ex situ X-ray diffraction result reveals that the lithium storage mechanism of Nb2Se9 is the conversion reaction. As an anode for sodium-ion batteries, Nb2Se9 delivered an initial reversible capacity of 342.60 mAh g–1 at the current density of 100 mA g–1 and was stabilized at 230.36 mAh g–1 over 500 cycles after the initial 50 cycles. Excellent electrochemical performance may be attributed to the special micro–nano hierarchical structure of the flower-like Nb2Se9 material, which greatly promotes ion diffusion and provides abundant active sites. These results indicate that flower-like Nb2Se9 is a promising anode material for both lithium-ion and sodium-ion batteries.

In this work, a flake-structured Co 2 B 2 O 5 material was obtained by a simple sol-gel method and researched for use in sodium ion batteries firstly. When serving as anode material for sodium ion batteries, it exhibits the high initial reversible capacity of 466 mAhÁg -1 at a current density of 100 mAÁg -1 . Through the recombination of carbon nanotubes (CNTs), the composite Co 2 B 2 O 5 /CNTs delivers the initial reversible capacity of 464 mAhÁg -1 , and 324 mAhÁg -1 is obtained after 60 cycles under the current density of 100 mAÁg -1 . When under the current density of 1000 mAÁg -1 , a capacity of 236 mAhÁg -1 is obtained for Co 2 B 2 O 5 /CNTs while 160 mAhÁg -1 for Co 2 B 2 O 5 . Moreover, the sodium storage behavior of Co 2 B 2 O 5 is identified by kinetic analysis. The higher Na ? capacitive contribution of Co 2 B 2 O 5 /CNTs could account for the enhanced rate performance. The results indicate that Co 2 B 2 O 5 is a promising anode material for sodium ion batteries.

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