Nickel-doped Li2MoO4 as a high-performance anode material for rechargeable lithium-ion batteries

Abstract

Transition metal oxides represent a promising anode material for rechargeable lithium-ion batteries (LIBs) because of their high theoretical specific capacity. Li2MoO4 (LMO) has a high specific capacity due to its variable oxidation state and alloying reaction, but the low conductivity and large volume expansion significantly impede its practical applications. To overcome these challenges, here we proposed a nickel-dopping strategy to prepare Li2NixMo1-xO4 (LNMO) as an anode of LIBs by dopping Li2MoO4 with Ni2+ ions using a sol-gel process. The Ni-dopping can not only help minimize the path length for ion and electron transport, thus enhancing electron transmission or conductivity, but also offers a mechanical cushion against volume expansion and contraction amid regular insertion and removal of Li+. As a result, as-developed LNMO anode exhibits a higher reversible charge/discharge specific capacity than LMO, in addition to excellent cycling stability. The Li2Ni0.05Mo0.95O4 anode exhibits a stable lithium storage capability of 487.2 mAh g-1, much higher than 210.9 mAh g-1 for the LMO anode after 100 times of charge/discharge cycles at a current density of 100 mA g-1. This work offers a facile yet effective approach to creating high-performance Li2MoO4 anode materials, thus promoting its real-world application in rechargeable LIBs.