调控木材基硬炭的开孔结构以提高钠离子电池负极性能OA

Hard carbon(HC)derived from renewable biomass is a promising anode material for sodium-ion batteries(SIBs).However,controlling the structure of hard carbon so that it has a high energy density,favorable rate performance,and cycling sta-bility is still a challenge.We propose a strategy to control the open pore structure of hard carbon derived from wood for sodium-ion storage by the addition of sodium carbonate under carbonization at 1100 ℃.The resulting HC has an increased interlayer spacing,and a more uniform open pore distribution(2-3 nm)with a high slope capacity,thereby enabling efficient sodium-ion transport and storage.The HC anode has a reversible capacity of 326 mAh g-1 at a current density of 30 mA g-1,and maintains a reversible capacity of 270 mAh g-1 at 1 A g-1 and a capacity of 68 mAh g-1 even at 10 A g-1 during rate performance tests.After 300 cycles,it retains 76.7%(207 mAh g-1)of its capacity at 1.0 A g-1.In situ Raman spectroscopy and the galvanostatic inter-mittent titration testing results reveal an adsorption-intercalation-filling sodium storage mechanism.This work provides a strategy to optimize the open pore structure of biomass derived hard carbon for high performance sodium ion storage.