Electrochemical Performance of the LiNi1 / 3Co1 / 3Mn1 / 3O2 in Aqueous Electrolyte

Abstract

with a well-ordered layered structure, which is confirmed by X-ray diffraction, was synthesized by the sol–gel method. The electrochemical performance of was investigated in a 2 M aqueous solution and in an organic solution. showed a much better rate capability in the aqueous solution than in the organic solution; both charge and discharge processes were finished in a few seconds. The cycle performance of the electrode with different charge/discharge rates from 80 to 200C was tested, and it exhibited good cycle performance in the aqueous solution with only 9.1% capacity loss after 1000 cycles at 80C (charge and discharge processes both within 20 s). The diffusion coefficients of lithium ion in the bulk of in the aqueous and organic solutions were calculated to be and , respectively, by slow scan cyclic voltammetry. The electrochemistry impedance spectrum indicates that in the aqueous solution is less than , which is 1–2 magnitude lower than in the organic solution. The fast and stable interfacial charge transfer in the aqueous solution should lead to improved electrochemical performance.