The invention relates to a positive
pole piece, a preparation method thereof and a
lithium ion battery. The preparation method of the positive
pole piece comprises the following steps: step 1, premixing a ternary material with
lithium manganate to prepare a
cathode active material; step 2, mixing the
cathode active material with a binder, a conductive agent and an
organic solvent, and pulping the mixture to obtain a stable
slurry; step 3, adding a certain amount of
lithium carbonate into the
slurry; step 4,
coating an
aluminum foil tape with the
slurry,
drying, rolling, and
slicing, so as to obtain the positive
pole piece. The positive pole piece prepared by adopting the preparation method provided by the invention improves the high temperature performance and the
cycling stability of lithium
ion batteries, greatly reduces the cost of materials, shortens the fusion time of the
cathode material, the binder and the conductive agent and improves the production efficiency; besides, as a defined amount of
lithium carbonate is added into the slurry,
electrolyte decomposition in the
cyclic process of batteries is effectively inhibited, and at the same time the
solid electrolyte interphase (SEI) film is endowed with better
viscoelasticity, the intercalation of lithium ions is facilitated, and both the electrochemical performance and the safety performance of batteries are further improved.