Cu 3 P Binary Phosphide: Synthesis via a Wet Mechanochemical Method and Electrochemical Behavior as Negative Electrode Material for Lithium‐Ion Batteries

Mechanochemical synthesis of Cu 3 P 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 3 P 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 3 P structure until the formation of Li 3 P 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 x Cu 3‐x P phase (0 ≤ × ≤ 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 3 P 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.