Ant-nest-like Cu2-xSe@C with biomimetic channels boosts the cycling performance for lithium storage

Progress on Copper-Based Anode Materials for Sodium-Ion Batteries

Fossil fuels have clearly failed to meet people's growing energy needs due to their limited reserves, potential pollution of the environment, and high costs. The development of cleaner, renewable energy sources as well as secondary batteries for energy storage is imminent, in a modern society where energy demand is soaring. Sodium-ion batteries (SIBs) have become the focus of large-scale energy storage systems as a promising alternative to lithium-ion batteries. The development of SIBs relies on the construction of high performance electrode materials. The design of low cost and high performance anode materials is a key link in this regard. Copper-based anodes are characterized by high theoretical capacity, abundant reserves, low cost and environmental friendliness. A variety of copper-based anode materials, which include cobalt oxides, sulfides, selenides and phosphides, have been synthesized and evaluated in the scientific literature for sodium storage. In detail, the preparation methods, response mechanisms, strengths and weaknesses, the relationship between morphology structure and electrochemical performance are discussed, as well as highlighting strategies to improve the electrochemical performance of copper-based anode materials. Finally, we offer our perspective on the challenges and potential for the development of copper-based anodes as a means of developing practical and high performing SIBs.

In-situ confining selenium within bubble - like carbon nanoshells for ultra-stable Li-Se batteries

Lithium-selenium (Li-Se) batteries are promising energy storage devices. However, the long-term durability and high-rate performance of the Se cathode have been limited by significant volume expansion and the troublesome shuttle effect of polyselenides during repeated charging/discharging processes. To revolutionize these issues, we applied a top-down strategy through the in-situ trapping of amorphous Se within bubble-like carbon (BLC) frameworks, which can radically minimize the presence of surface-absorbed Se while enhancing Se loading capacity. This ingenious technique successfully encapsulates all Se species within carbon nanoshells, creating a distinct half-filled core-shell structure known as Se@void@BLC. This in-situ trapping approach ensures the efficient management of Se volume changes during repeated discharge and charge cycles. Moreover, an extraordinary Se loading capacity of up to 65.6 wt% is reached. Using the Se@void@BLC as cathode for Li-Se battery, we achieve a high initial Columbic efficiency of 84.2 %, a high reversible capacity of 585 mAh g-1, and an ultralow capacity decay of only 0.0037 % per cycle during 4000 cycles at 10 A g-1.