In-situ measurement technique for nondestructive determination of end-of-mixing time during slurry preparation for battery manufacturing process
A method of producing an electrode slurry for use in battery manufacturing includes mixing a plurality of slurry components within an internal volume of a mixing container, transmitting ultrasonic signals across the internal volume of the mixing container, monitoring an attenuation of the ultrasonic signals over a period of time, determining when an end-of-mixing condition is met when the acoustic attenuation reaches a predetermined value, and stopping the mixing when the end-of-mixing condition is met.
1 . A method of producing an electrode slurry for use in battery manufacturing, the method comprising:
mixing a plurality of slurry components within an internal volume of a mixing container;
transmitting acoustic signals across the internal volume of the mixing container;
monitoring an acoustic attenuation of the acoustic signals over a period of time;
determining when an end-of-mixing condition is met when the acoustic attenuation reaches a predetermined value; and
stopping the mixing when the end-of-mixing condition is met.
2 . The method of claim 1 , wherein the predetermined value is a target value of the acoustic attenuation.
3 . The method of claim 1 , wherein the predetermined value is a rate of change of an acoustic attenuation coefficient.
4 . The method of claim 1 , wherein the plurality of slurry components comprise carbon and a polyvinylidene fluoride (PVDF) binder.
5 . The method of claim 1 , wherein the acoustic signals are transmitted by a plurality of transducers located at a plurality of heights on the mixing container.
6 . The method of claim 1 , wherein a plurality of acoustic signals are transmitted by an array of transducers.
7 . A method of producing an electrode slurry for use in battery manufacturing, the method comprising:
mixing a plurality of slurry components within an internal volume of a mixing container;
transmitting ultrasonic signals across the internal volume of the mixing container;
monitoring an attenuation of the ultrasonic signals over a period of time;
determining when an end-of-mixing condition is met when the acoustic attenuation reaches a predetermined value; and
stopping the mixing when the end-of-mixing condition is met.
8 . The method of claim 7 , wherein the predetermined value is a target value of the attenuation of the ultrasonic signals.
9 . The method of claim 7 , wherein the predetermined value is a rate of change of the attenuation of the ultrasonic signals.
10 . The method of claim 7 , wherein the ultrasonic signals are transmitted and received by an array of ultrasonic transducers.
11 . A method of producing an electrode slurry for use in battery manufacturing, the method comprising:
mixing a plurality of slurry components within an internal volume of a mixing container;
transmitting acoustic signals across the internal volume of the mixing container;
monitoring an attenuation for the acoustic signals over a period of time; and
adjusting at least one mixing parameter based on the attenuation the acoustic signals.
12 . The method of claim 11 , wherein the acoustic signals are transmitted and received by a plurality of acoustic transducers.
13 . The method of claim 12 , wherein the acoustic transducers are located on an outside of the mixing container.
14 . The method of claim 12 , wherein the acoustic transducers are located on an inside of the mixing container.
15 . The method of claim 12 , wherein the acoustic transducers are located at a plurality of heights on the mixing container.
16 . The method of claim 12 , wherein the acoustic signals are transmitted and received by an array of acoustic transducers.
17 . The method of claim 11 , wherein the mixing parameter is adjusted based on a rate of change of the attenuation of at least one of the plurality of acoustic signals.
18 . The method of claim 11 , wherein the mixing parameter is selected from a group consisting of: a mixing speed, a mixing start, and a mixing stop.
19 . The method of claim 11 , wherein the mixing parameter is selected from a group consisting of a location of a mixing blade within the internal volume and an angle of the mixing blade.
20 . The method of claim 11 , wherein the mixing parameter is a mixing profile.