The invention relates to the technical field of
lithium ion batteries, and particularly relates to a high-stability long-service-life
metal lithium negative
electrode material and a preparation methodthereof, and more particularly relates to a method for passivating the surface of
metal lithium by utilizing low-temperature
gallium-based
liquid metal, reducing the reaction activity of the
metal lithium and stabilizing a metal lithium negative
electrode. The high-stability long-service-life
lithium metal negative
electrode material is
lithium metal with an optimized lithium-based
alloy passivation layer. The method comprises the steps of
coating the surface of metal lithium with a layer of low-temperature
gallium-based
liquid metal, and then carrying out alloying reaction in an
inert atmosphere so as to obtain the product. The low-temperature
gallium-based
liquid metal which is low in
melting point, good in flowability, good in
conductivity, lithium-friendly and non-toxic is used for
coating the surface of the metal lithium with high reaction activity; and a lithium-based
alloy passivation layer with good lithium affinity,
corrosion resistance and high
ion diffusion coefficient is formed on the surface of the metal lithium, so that the
nucleation barrier of lithium is reduced, the electrochemical dynamics of an
electrode interface is accelerated, the
cycling stability of the metal lithium is improved, and the service life of the metal lithium is prolonged.