Sn4P3 has been recognized as a promising candidate for an anode material for lithium-ion batteries (LIBs) because of its appropriate operating potential and high theoretical capacity. Unfortunately, the rapid fading of capacity induced by volume change, low electrical conductivity, and limited lithium-ion charging speed hindered the actual application of Sn4P3. Building physical barriers of carbon-based material on the surface of Sn4P3 particles is a common way to handle the above issues. In our work, Sn4P3 particles were confined in an ordered mesoporous carbon framework (CMK-3) via a low-pressure vapor method. CMK-3 can not only improve the electric conductivity but also buffer the volume effect by using its mesopore channels to provide accommodation for the huge volume expansion of Sn4P3 particles. In addition, Sn4P3 nanoparticles were synthesized in CMK-3 frameworks via a low-pressure vapor method to obtain the Sn4P3/CMK-3 nanocomposite. The nanosize effect can shorten electron transfer distance, leading to faster reaction kinetics to improve electrochemical performance. The Sn4P3/CMK-3 was further grafted by a thin layer of poly(3,4-ethylenedioxythiophene) (PEDOT) to prevent the continuing buildup of poorly conducting species and thus optimize the solid electrolyte interface, which has been evidenced by in-depth X-ray photoelectron spectroscopy via Ar cluster etching. As a result of the dual-confining strategy, Sn4P3/CMK-3@PEDOT showed relatively high rate performance (reversible capacity of 438 mAh g–1 at 2.0 A g–1) and stable cycling performance (923 mAh g–1 at 0.5 A g–1 over 740 cycles).
