Ultra-high Li storage capacity achieved by hollow carbon capsules with hierarchical nanoarchitecture

Abstract

Hollow core–mesoporous shell carbon (HCMSC) with hierarchical nanoarchitecture was prepared and explored as an anode with ultra-high Li storage capacity in Li ion batteries. Compared with commercial graphite and ordered mesoporous carbon (CMK-3), the HCMSC not only demonstrates higher Li storage capacity, but also better cycling performance and rate capability. HCMSC possesses unique structural characteristics such as large surface area and mesopore volume. Particularly the hierarchical macro-scaled hollow core/mesoporous shell nanostructure along with 3D large interconnected interstitial volume guarantees fast mass transport in HCMSC, resulting in ultra-high Li storage capacity and excellent cycling performance and rate capability. Furthermore, the hollow macro-scaled core encapsulated in a well-developed 3D interconnected mesoporous shell serves as an efficient Li storage and buffer reservoir to reduce volume change during the charge–discharge cycling especially at high rates, which contributes greatly to the enhanced cycling performance and rate capability.