Abstract
Tin (Sn) is a prominent anode material for improving the performances of Li-ion batteries (LIBs) thanks to its abundance and high theoretical capacity. However, Sn is hardly applied in industry because it suffers from large volume expansion during cycling, resulting in poor reliability. Although various synthesis methods have been applied to overcome these issues, most strategies focus on combining nano-sized Sn active material with nanoporous carbonaceous binders to buffer volume expansion and improve intrinsic electrical conductivity. However, this implies a reduction in the fraction of active Sn nanomaterial by the binders and contradicts the trend towards increasing the energy density of LIBs. In this paper, we propose a facile and ultrafast method to fabricate binder-free Sn electrodes at ambient conditions using the intense pulsed light (IPL) method. Sn nanoparticles (Sn NPs) inks (10 and 20 nm) were first prepared using chemical methods and inkjet-printed onto copper foil before IPL. We show that meticulous tuning of the IPL parameters to the optimal condition results in heating above the melting temperature of Sn NPs while maintaining the film morphology and nanoparticle size. This pre-melting condition leads to the local transformation of organic ligands into an amorphous carbon shell, reduces the thickness of the native Sn oxide shell and subsequently enhances electron transfer between Sn NPs. Finally, we demonstrate that these electrically conductive Sn anodes exhibit outstanding specific capacities of (over 700 mAh g −1 after 200 cycles at 1C) with good cycling stability and rate capability. • IPL selective heat treatment of inkjet-printed Sn nanoparticles under ambient conditions achieves high electrical conductivity. • IPL induces surface pre-melting of Sn nanoparticles without causing morphological changes. • Binder-free Sn anodes exhibit excellent electrochemical performance. • IPL performed in milliseconds, can be easily integrated into large-scale industrial manufacturing processes.