Three-dimensional B-doped porous carbon framework anchored with ultrasmall PbO/Pb nanocrystals for lithium storage

Abstract

Abstract This work provides a Pb-based anode material consisting of uniform spherical PbO/Pb nanocrystals (NCs, ~ 14 nm) tightly anchored within three-dimensional B-doped porous carbon framework (3D-BPCF). This nanocomposite with the BET specific surface area of 79.06 m 2 g −1 , for the first time, was produced by pyrolyzing starch xerogel permeated Pb 2+ and boron. When used as an anode for LIBs, it could deliver a large initial discharge capacity of 569 mA h g −1 and a capacity retention of 400 mA h g −1 after 200 cycles at a current density of 0.2 A g −1 . Further, it delivers a reversible capacity of ~ 240 mA h g −1 at a high current density of 2 A g −1 . The lithium storage properties is superior than most of reported Pb-based materials, which was mainly attributed to the synergy between ultrasmall PbO/Pb NCs and conductive 3D-BPCF. Also, metallic Pb NCs adjacent PbO in the nanocomposite increases the reversibility of the conversion reaction of PbO, resulting in superior cyclic performance and lithium storage capacity. Moreover, an effective combination between PCF and PbO/Pb NCs formed by doping boron limits the aggregation and exfoliation of in-situ created PbO/Pb NCs, resulting in a stable integrity of the whole electrode with long cycle life.