A cooperative biphasic MoOx–MoPx promoter enables a fast-charging lithium-ion battery
Sang-Min Lee, Junyoung Kim, Janghyuk Moon, Kyu-Nam Jung, Jong Hwa Kim, Gum-Jae Park, Jeong‐Hee Choi, Dong Young Rhee, Jeom-Soo Kim, Jong-Won Lee, Min‐Sik Park
Abstract
Abstract The realisation of fast-charging lithium-ion batteries with long cycle lifetimes is hindered by the uncontrollable plating of metallic Li on the graphite anode during high-rate charging. Here we report that surface engineering of graphite with a cooperative biphasic MoO x –MoP x promoter improves the charging rate and suppresses Li plating without compromising energy density. We design and synthesise MoO x –MoP x /graphite via controllable and scalable surface engineering, i.e., the deposition of a MoO x nanolayer on the graphite surface, followed by vapour-induced partial phase transformation of MoO x to MoP x . A variety of analytical studies combined with thermodynamic calculations demonstrate that MoO x effectively mitigates the formation of resistive films on the graphite surface, while MoP x hosts Li + at relatively high potentials via a fast intercalation reaction and plays a dominant role in lowering the Li + adsorption energy. The MoO x –MoP x /graphite anode exhibits a fast-charging capability (<10 min charging for 80% of the capacity) and stable cycling performance without any signs of Li plating over 300 cycles when coupled with a LiNi 0.6 Co 0.2 Mn 0.2 O 2 cathode. Thus, the developed approach paves the way to the design of advanced anode materials for fast-charging Li-ion batteries.