The creation of hollow walls in carbon nanotubes for high-performance lithium ion batteries

Although high mechanical and electronic properties have made carbon nanotube (CNT) a promising active material for lithium ion batteries, the relatively low theoretical specific capacity (372 mAh g−1) of CNT has hindered its application. Here we have developed a general and efficient template strategy in synthesizing a new family of CNTs with controllable hollow walls and explored their promising applications in LIBs. The hollow structure formed between CNT core and nitrogen-doped graphene shell can be effectively used for lithium storage, and a reversible specific capacity of 635 mAh g−1 was achieved as anode material in LIB. Interestingly, the hollow structure has been further incorporated with silicon to offer even higher specific capacity of 930 mAh g−1 with good cyclic stability.