Cu_3P Binary Phosphide: Synthesis via a Wet Mechanochemical Method and Electrochemical Behavior as Negative Electrode Material for Lithium-Ion Batteries

摘要

Mechanochemical synthesis of Cu_3P in the presence of n-dodecane results in a material with a secondary particle size distribution of 10 μm, secondary particles which consist of homogeneously agglomerated 20 nm primary particles. The electrochemical performance of Cu_3P with lithium is influenced by the reaction depth, in other words by the lower potential cut-off. During the electrochemical reaction, the displacement of copper by lithium from the Cu_3P structure until the formation of Li_3P and Cu deteriorates the capacity retention. Improved performance was obtained when the charge potential was limited to 0.50 V (vs. Li/Li) and the formation of the Li_xCu_(3-x) P phase (0 ≤ x ≤ 2). In this case, when the potential is limited to 0.5 V, the capacity is stable for more than 50 cycles. Acceptable electrochemical performances in Li-ion cells within the voltage range 0.50-2.0 V (vs. Li/Li~+) were shown when Cu_3P was used as an anode and Li_(1.2)(Ni_(0.13)Mn_(0.54)Co_(0.13)O_2 and LiNi_(0.5)Mn_(1.5)O_4 as positive electrode materials.