Pb/C Composite with Spherical Pb Nanoparticles Encapsulated in Carbon Microspheres as a High-Performance Anode for Lithium-Ion Batteries

The appropriate exploitation of the plentiful recycled Pb from discarded lead-acid batteries is both challenging and profitable, which can alleviate lead pollution and provide the advantage of using Pb as the potential resource. Pb with a high theoretical capacity (569 mA h g(-1)), excellent electrical conductivity, low price, and high safety demonstrates great potential as an anode for lithium-ion batteries (LIBs). Herein, the Pb/C composite with a "spherical Pb nanoparticles encapsulated in carbon microspheres" (PNCM) structure is synthesized via a hydrothermal method, demonstrating an attractive capacity of 852/443 mA h g(-1) after 850/2000 cycles at 0.5/1 A g(-1) as an anode material for LIBs. The Pb nanoparticles with a size of 20-50 nm are uniformly distributed in the carbon microspheres. The carbon matrix as a barrier effectively prevents the aggregation and volume expansion of Pb nanoparticles during the cycling process. To make further improvement in electrochemical performance, a flexible binder-free PNCM-carbon nanotube (CNT) film (PCF) electrode is prepared without a polymeric binder and a metal current collector. The absence of the binder and the uniform distribution of CNTs endow the PCF electrode with excellent electrical conductivity. The PCF electrode shows a prominent improvement in electrochemical performance compared with a PNCM electrode, displaying a capacity of as high as 705 mA h g(-1) after 2000 cycles at 1 A g(-1).