Systems and methods for evaluating electrolyte wetting and distribution

Abstract

Systems and techniques for measuring process characteristics including electrolyte distribution in a battery cell. A non-destructive method for analyzing a battery cell includes determining acoustic features at two or more locations of the battery cell, the acoustic features based on one or more of acoustic signals travelling through at least one or more portions of the battery cell during one or more points in time or responses to the acoustic signals obtained during one or more points in time, wherein the one or more points in time correspond to one or more stages of electrolyte distribution in the battery cell. One or more characteristics of the battery cell are determined based on the acoustic features at the two or more locations of the battery cell.

What is claimed is: 
     
         1 . A method of analyzing a battery cell, the method comprising:
 determining acoustic features at two or more locations of the battery cell, the acoustic features based on one or more of acoustic signals transmitted through a battery cell;   
       generating a score based on the acoustic features, the score being an index of homogeneity of electrolyte distribution in the battery cell; and 
       assessing the battery cell using the score. 
     
     
         2 . The method of  claim 1 , further comprising:
 creating a two-dimensional map based on the acoustic features at two or more locations across the battery cell, wherein assessing the battery cell is based on the two-dimensional map.   
     
     
         3 . The method of  claim 1 , further comprising:
 applying a dimension reduction algorithm on the acoustic features to determine the score.   
     
     
         4 . The method of  claim 1 , wherein the one or more acoustic signals are transmitted at one or more points in time, the one or more points in times at which one or more of process steps occur, the one or more process steps comprising soaking, formation, self-discharge aging of the battery cell, or one or more charge/discharge cycles of the battery cell. 
     
     
         5 . The method of  claim 1 , wherein the battery cell is assessed to determine one or more characteristics of the battery cell, the one or more characteristics including at least one of battery cell quality, ideal soaking time, process drifts, and manufacturing defects. 
     
     
         6 . The method of  claim 5 , wherein the manufacturing defects comprise one or more of contamination, dry spots, voids, electrode and separator folds or tears. 
     
     
         7 . The method of  claim 1 , wherein the battery cell is assessed to determine battery cell performance corresponding to one or more of teardown analysis, formation capacity, Electrochemical Impedance Spectroscopy (EIS), self-discharge aging, or charge/discharge cycling. 
     
     
         8 . The method of  claim 1 , wherein the acoustic features comprise one or more of a time-of-flight, centroid (mean) frequency, first break time, first peak, amplitude, or standard deviation of frequency of the acoustic signals. 
     
     
         9 . An apparatus comprising:
 one or more memories configured to store computer-readable instructions;   one or more processors configured to execute the computer-readable instructions to:   determine acoustic features at two or more locations of a battery cell, the acoustic features based on one or more of acoustic signals transmitted through a battery cell;   
       generate a score based on the acoustic features, the score being an index of homogeneity of electrolyte distribution in the battery cell; and 
       assess the battery cell using the score. 
     
     
         10 . The apparatus of  claim 9 , wherein the one or more processors are further configured to execute the computer-readable instructions to create a two-dimensional map based on the acoustic features at two or more locations across the battery cell, wherein the battery cell is assessed based on the two-dimensional map. 
     
     
         11 . The apparatus of  claim 9 , wherein the one or more processors are further configured to execute the computer-readable instructions to apply a dimension reduction algorithm on the acoustic features to determine the score. 
     
     
         12 . The apparatus of  claim 9 , wherein the one or more acoustic signals are transmitted at one or more points in time, the one or more points in times at which one or more of process steps occur, the one or more process steps comprising soaking, formation, self-discharge aging of the battery cell, or one or more charge/discharge cycles of the battery cell. 
     
     
         13 . The apparatus of  claim 9 , wherein the battery cell is assessed to determine one or more characteristics of the battery cell, the one or more characteristics including at least one of battery cell quality, ideal soaking time, process drifts, and manufacturing defects. 
     
     
         14 . The apparatus of  claim 13 , wherein the manufacturing defects comprise one or more of contamination, dry spots, voids, electrode and separator folds or tears. 
     
     
         15 . The apparatus of  claim 9 , wherein the battery cell is assessed to determine battery cell performance corresponding to one or more of teardown analysis, formation capacity, Electrochemical Impedance Spectroscopy (EIS), self-discharge aging, or charge/discharge cycling. 
     
     
         16 . One or more non-transitory computer-readable media comprising computer-readable instructions, which when executed by one or more processors, cause the one or more processors to:
 determine acoustic features at two or more locations of a battery cell, the acoustic features based on one or more of acoustic signals transmitted through a battery cell;   
       generate a score based on the acoustic features, the score being an index of homogeneity of electrolyte distribution in the battery cell; and 
       assess the battery cell using the score. 
     
     
         17 . The one or more non-transitory computer-readable media of  claim 16 , wherein the execution of the computer-readable media further cause the one or more processors to create a two-dimensional map based on the acoustic features at two or more locations across the battery cell, wherein the battery cell is assessed based on the two-dimensional map. 
     
     
         18 . The one or more non-transitory computer-readable media of  claim 16 , wherein the execution of the computer-readable media further cause the one or more processors to apply a dimension reduction algorithm on the acoustic features to determine the score. 
     
     
         19 . The one or more non-transitory computer-readable media of  claim 16 , wherein the one or more acoustic signals are transmitted at one or more points in time, the one or more points in times at which one or more of process steps occur, the one or more process steps comprising soaking, formation, self-discharge aging of the battery cell, or one or more charge/discharge cycles of the battery cell. 
     
     
         20 . The apparatus of  claim 9 , wherein the battery cell is assessed to determine one or more characteristics of the battery cell, the one or more characteristics including at least one of battery cell quality, ideal soaking time, process drifts, or manufacturing defects, the manufacturing defects being one or more of contamination, dry spots, voids, electrode and separator folds or tears.