Nitrogen-doped hierarchically porous carbonaceous nanotubes for lithium ion batteries

By a novel two-step activation of the polypyrrole nanotube (PPyNT) precursor, nitrogen-doped hierarchically porous carbonaceous nanotubes (HPCNT) are successfully prepared. The as-prepared HPCNT not only exhibits an ultrahigh specific surface area of 2180 m(2) g(-1) and a large total pore volume of 1.22 cm(3) g(-1), but also possesses a rich N-doping content of 8.2 wt% which especially includes a high pyridinic-N content of 30%. As an anode for lithium-ion batteries (LIBs), the HPCNT delivers an ultrahigh reversible capacity of 1372 mAh g(-1) and keeps a high retention of 89.3% over 100 cycles at 0.1 A g(-1). Even at a large current rate of 1 A g(-1), the reversible capacity is still as high as 630 mAh g(-1) after 700 cycles. Compared with either the commercial graphite or the state-of-the-art LIB carbons in the literature, the HPCNT is quite competitive, which makes it a promising anode material for next-generation LIBs. Also, the outstanding performances of the HPCNT exhibit a great potential of this novel activation strategy for commercial application on LIBs.