title: Nitrogen-doped multiwall carbon nanotubes for lithium storage with extremely high capacity.
abstract: The increasing demands on high performance energy storage systems have raised a new class of devices, so-called lithium ion capacitors (LICs). As its name says, LIC is an intermediate system between lithium ion batteries and supercapacitors, designed for taking advantages of both types of energy storage systems. Herein, as a quest to improve the Li storage capability compared to that of other existing carbon nanomaterials, we have developed extrinsically defective multiwall carbon nanotubes by nitrogen-doping. Nitrogen-doped carbon nanotubes contain wall defects through which lithium ions can diffuse so as to occupy a large portion of the interwall space as storage regions. Furthermore, when integrated with 3 nm nickel oxide nanoparticles for a further capacity boost, nitrogen doping enables unprecedented cell performance by engaging anomalous electrochemical phenomena such as nanoparticles division into even smaller ones, their agglomeration-free diffusion between nitrogen-doped sites as well as capacity rise with cycles. The final cells exhibit a capacity as high as 3500 mAh/g, a cycle life of greater than 10,000 times, and a discharge rate capability of 1.5 min while retaining a capacity of 350 mAh/g.
authors.affiliation: Graduate School of EEWS (WCU), Korea Advanced Institute of Science and Technology, 373-1 Guseong Dong, Yuseong Gu, Daejon 305-701, Korea.
authors.forename: Weon Ho
authors.initials: WH
authors.lastname: Shin
authors.forename: Hyung Mo
authors.initials: HM
authors.lastname: Jeong
authors.forename: Byung Gon
authors.initials: BG
authors.lastname: Kim
authors.forename: Jeung Ku
authors.initials: JK
authors.lastname: Kang
authors.forename: Jang Wook
authors.initials: JW
authors.lastname: Choi