Agar-derived nitrogen-doped porous carbon as anode for construction of cost-effective lithium-ion batteries

Balancing cost and performance of porous carbon(PC)as anode for lithium-ion battery(LIBs)is the key to effectively promote commercial application.Herein,low-cost N-doped PC(NPC-Ts,T=600,750 and 900°C)were facilely prepared in batches via one-pot pyrolysis of agar with different carbonization temperature.The NPC-750 with specific surface area of 2914 m^(2)/g and N content of 2.84%exhibits an ultrahigh reversible capacity of 1019 mAh/g at 0.1 A/g after 100 cycles and 837 mAh/g at 1 A/g after 500 cycles.Remarkably,the resulting LIBs exhibit an ultrafast charge-discharge feature with a remarkable capacity of 281 mAh/g at 10 A/g and a superlong cycle life with a capacity retention of 87%after 5000 cycles at 10 A/g.Coupling with LiFePO_(4)cathode,the fabricated lithium-ion full cells possess high capacity,excellent rate and cycling performances(125 mAh/g at 100 mA/g,capacity retention of 95%,after 220 cycles),highlighting the practicability of this NPC-750 as the anode materials.