METHOD FOR PREDICTING SPECIFIC CAPACITY OF GRAPHITE ANODIC MATERIAL OF LITHIUM-ION BATTERY Russian patent published in 2023 - IPC G01N27/26 

FIELD: electrochemical energy.

SUBSTANCE: invention can be used in the field of material control in the production of lithium-ion batteries. A method for predicting the specific capacity of a graphite anode material of a lithium-ion battery includes preparing and carrying out physical and chemical testing of samples, taking measurements on the surface of the samples with placing a pressing electrochemical cell with an acidic electrolyte on their surface, supplying an input signal and receiving a measured signal, assembling an electrochemical cell with obtaining cyclic voltammetric dependences and hodographs of electrochemical impedance, processing the obtained data based on a system of linear regression equations constructed from training samples of samples with known values of the predicted parameters. Physicochemical control is carried out, which consists of measuring the pH of the aqueous extract of powdered graphite anode material. Electrodes are used as samples, which are prepared by preparing a mixture of powdered graphite anode material with a binder, applying it to the electrode collectors, drying and rolling the electrodes. Measurements are carried out on the surface of the resulting electrodes in a pressure electrochemical cell, in which a stepwise changing potential with a step duration of 20-180 s and a step value of 15-20 mV is used as an input signal, and the dependence of the amounts of electricity on the step potentials is used as the measured signal. Two electrochemical cells are prepared in the form of disk elements of type 2016, each of which contains a lithium electrode, a separator, electrode samples, an electrolyte. An electrochemical impedance hodograph is obtained in one electrochemical cell, and in the other, cyclic voltammetric dependences are obtained in the potential range: 5-1500 mV at potential scan rates of 4-100 mV/s. Processing the obtained data based on a system of linear regression equations includes finding the total amount of electricity depending on the amount of electricity on the potential in the potential region minus 700 - 0 mV, finding the angular coefficient of the dependence of the maximum current density on the square root of the potential sweep rate, determining the parameters Rs and CPE-T of the equivalent circuit of the Rs-CPE electrochemical cell in the frequency range 0.1-100 Hz, determining whether the data belongs to one of four clusters on the pH-amount of electricity plane in the potential range minus 700 - 0 mV, the boundaries of which are determined based on the results of data clustering for samples with known specific capacitance values, selecting a multiple regression design equation to calculate the predicted capacitance, each of which is based on data from samples for which the specific capacitance is known.

EFFECT: reducing the time to obtain the capacity prediction result.

1 cl, 4 dwg