RESUMEN
Hard carbon (HC) is a promising anode material in alkali metal ion batteries owing to its cost-effectiveness, abundant sources, and low working voltage. However, challenges persist in achiving prolonged cycling stability and consistent capacity, and the sodium storage mechanism in HC is still debated. Herein, an unreported biomass precursor, "sisal," for deriving hard carbon is developed. A series of sisal hemp-derived hard carbon with natural 3D porous channels are prepared. Through phase characterization and electrochemical testing, the relationship between microstructure and sodium storage capacity is elucidated, further confirming the suitability of the "adsorption-insertion-filling" mechanism for sodium storage properties in hard carbon materials. Without the need for any additional modification strategies, this biomass-derived hard carbon demonstrates excellent electrochemical performance in both sodium-ion and potassium-ion batteries (SIBs and PIBs). The as-prepared HC-1300 demonstrates excellent ion storage capability, delivering a high reversible capacity of 345.2 mAh g-1 in SIBs and 310 mAh g-1 in PIBs at 0.1 C. Moreover, it maintains a specific capacity of 237.3 mAh g-1 over 1200 cycles at 1 C when used in SIBs. The excellent cycling stability and superior rate performance are also presented in full cells, highlighting its potential for practical applications.
RESUMEN
Rechargeable zinc-ion batteries (ZIBs) are attractive for large-scale energy storage due to their superiority in resources, safety, and environmental friendliness. However, the lack of suitable ZIBs cathode materials limits their practical applications. In consideration of the excellent electrochemical performance of phosphate materials in monovalent ion (Li+ , Na+ ) batteries, they were also employed as ZIBs cathode materials recently and performed well with high potential. But they also suffer from low capacity and poor conductivity, and the energy storage mechanism is not clear yet. This Review provides a state-of-the art overview on the developments of phosphate cathode materials in ZIBs, including NASICON-type phosphates, fluorophosphates, olivine-structured, layered-structured, and novel-structured phosphate materials mainly. This study presents the reaction mechanism and electrochemical performance of phosphate cathode materials in aqueous ZIBs, and future research directions are discussed, which are intended to provide guidance for exploring high-potential cathode materials for ZIBs.