A carbon coated NASICON structure material embedded in porous carbon enabling superior sodium storage performance: NaTi2(PO4)3as an example

摘要: Sodium super ion conductor (NASICON) type structure materials (e.g. Na3V2(PO4)3, NaTi2(PO4)3) have been considered as promising electrode for sodium-ion batteries (NIBs). However, the inherent poor electronic conductivity of NASICON owing to their phosphates leads cyclability and rate capability. Here, we develop a general strategy achieve high capability long cycle life by preparing "double carbon coating" NaTi2(PO4)3 using soft-chemical method. The obtained carbon-coated within porous matrix (denoted NTP@C@PC) imparts reversible 103 mA h g(-1) at 5 C after 5000 cycles 64 50 sodium storage. capacity, stable excellent NTP@C@PC are attributed advantages special structure: fast Na(+)/e(-) transfer in nanocomposites, large surface area mesoporous nature 3D that facilitate electrolyte soak in, an intimate interaction between particles matrix. In addition, could effectively accommodate volume variation during repeated sodiation/desodiation process.