# US 2018/0323463 A1 · Method of manufacturing a fuel cell stack > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0323463 A1 - Document ID: US20180323463A1 - Status: Published application - Kind: A1 - Application number: 15/586,514 - Filed: 2017-05-04 - Published: 2018-11-08 - Earliest claimed: 2017-05-04 - Assignees: GM Global Technology Operations LLC - Applicants: GM Global Technology Operations LLC - Inventors: Xi Yang; Liang Xi; Jeffrey A. Rock; Siguang Xu; Yeh-Hung Lai - Web page: https://patentgrep.com/patent/US20180323463A1 ## CPC - H01M 8/2404: Processes or apparatus for grouping fuel cells - H01M 8/242: comprising framed electrodes or intermediary frame-like gaskets (H01M8/2425, H01M8/244 take precedence) - H01M 2008/1095: {Fuel cells with polymeric electrolytes} - Y02E 60/50: Fuel cells - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A method for assembling a fuel cell stack for a vehicle is provided wherein the method includes the steps of: (1) providing a batch of fuel cells having varying active area thicknesses among each fuel cell; (2) measuring an active area thickness for each fuel cell in the batch of fuel cells and sorting each fuel cell in the batch of fuel cells into one of a first group, a second group, and a third group based on the active area thickness for each fuel cell; (3) assembling a target number of fuel cells to a target height from at least one of the first, second and third groups onto a first end plate; and (4) affixing a second end plate to the target number of fuel cells and the first end plate thereby creating a fuel cell stack. ## Claims ### Claim 1 A method for assembling a fuel cell stack, the method comprising the steps of: providing a batch of fuel cells, each fuel cell in the batch of fuel cells having an active area thickness and a tolerance for the active area thickness; measuring an active area thickness for each fuel cell in the batch of fuel cells and sorting each fuel cell in the batch of fuel cells into one of a first group, a second group, and a third group based on the active area thickness for each fuel cell; assembling a target number of fuel cells to a target height from at least one of the first, second and third groups onto a first end plate; and affixing a second end plate to the target number of fuel cells and the first end plate thereby creating a fuel cell stack. ### Claim 2 (depends on 1) The method as defined by claim 1 wherein the step of measuring and sorting includes the step of directing a nominal fuel cell to the first group, directing a thin fuel cell to the second group, and directing a thick fuel cell to the third group. ### Claim 3 (depends on 2) The method as defined by claim 2 wherein the step of assembling the target number of fuel cells includes the step of alternating thick and thin fuel cells onto the first end plate. ### Claim 4 (depends on 2) The method as defined by claim 2 wherein the step of assembling the target number of fuel cells includes the step of providing thick, nominal and thin fuel cells in a repeated consecutive pattern onto the first end plate. ### Claim 5 (depends on 2) The method as defined by claim 2 wherein the step of assembling the target number of fuel cells includes the step of providing a plurality of nominal fuel cells adjacent to one another onto the first end plate. ### Claim 6 (depends on 3) The method as defined by claim 3 wherein the tolerance of the active area thickness for each nominal fuel cell falls in a range of about −10 μm to about 10 μm, the tolerance of the active area thickness for each thin fuel cell falls in a range of about −25 μm to about −10 μm, and the tolerance of the active area thickness for each thick fuel cell falls in a range of about 10 μm to about 25 μm. ### Claim 7 (depends on 4) The method as defined by claim 4 wherein the active area thickness for each nominal fuel cell has the tolerance which falls in a range of about −10 μm to about 10 μm, the active area thickness for each thin fuel cell has the tolerance which falls in a range of about −25 μm to about −10 μm, and the active area thickness for each thick fuel cell has the tolerance that falls in a range of about 10 μm to about 25 μm. ### Claim 8 (depends on 5) The method as defined by claim 5 wherein the tolerance for each active area thickness for each nominal fuel cell falls in a range of about −10 μm to about 10 μm, the tolerance for each active area thickness for each thin fuel cell falls in a range of about −25 μm to about −10 μm, and the tolerance for active area thickness for each thick fuel cell falls in a range of about 10 μm to about 25 μm. ### Claim 9 A method for assembling a fuel cell stack, the method comprising the steps of: providing a batch of fuel cells, each fuel cell in the batch of fuel cells having an active area thickness and a tolerance for the active area thickness; measuring an active area thickness for each fuel cell in the batch of fuel cells and sorting each fuel cell into one of a first group, a second group, and a third group; assembling a first plurality of fuel cells from any one of the first, second and third groups onto a first end plate until at least one of the first, second and third groups is depleted; assembling a second plurality of fuel cells to the first plurality of fuel cells until a target number of fuel cells is achieved, the second plurality of fuel cells being formed from any one of the first, second and third groups of fuel cells; and affixing a second end plate to the first plurality of fuel cells and the first end plate thereby creating a fuel cell stack. ### Claim 10 (depends on 9) The method as defined by claim 9 wherein the step of measuring and sorting includes the step of directing a nominal fuel cell to the first group, directing a thin fuel cell to the second group, and directing a thick fuel cell to the third group. ### Claim 11 (depends on 10) The method as defined in claim 10 wherein the first plurality of fuel cells is formed from alternating thin and thick fuel cells, and the second plurality of fuel cells is composed of nominal fuel cells. ### Claim 12 (depends on 10) The method as defined in claim 10 wherein the first plurality of fuel cells is formed solely from a plurality of nominal fuel cells, and the second plurality of fuel cells is formed from at least one of a thin fuel cell and a thick fuel cell. ### Claim 13 (depends on 11) The method as defined in claim 11 wherein the second group is defined by at least one fuel cell having the a thin active area thickness which the tolerance falls in a range of about −25 μm to about −10 μm, and the third group is defined by at least one fuel cell having a thick active area thickness of which the tolerance falls within a range of about 10 μm to about 25 μm. ### Claim 14 (depends on 12) The method as defined in claim 12 wherein the second group is defined by at least one fuel cell having a thin active area thickness with a tolerance which falls in a range of about −25 μm to about −10 μm, and the third group is defined by at least one fuel cell having a thick active area thickness with a tolerance which falls in the range of about 10 μm to about 25 μm. ### Claim 15 (depends on 12) The method as defined in claim 12 wherein the step of assembling a second plurality of fuel cells onto the first plurality of fuel cells includes the step of alternating thin and thick fuel cells in a consecutive pattern within the second plurality of fuel cells. ### Claim 16 A method for assembling a fuel cell stack, the method comprising the steps of: providing a batch of fuel cells, each fuel cell in the batch of fuel cells having an active area thickness and a tolerance for the active thickness; measuring an active area thickness for each fuel cell in the batch of fuel cells and sorting each fuel cell into one of a first group, a second group, and a third group; randomly assembling a first plurality of fuel cells from any one or more of the first, second and third groups onto a first end plate until at least 50 percent of a target fuel cell number is achieved; selectively assembling a second plurality of fuel cells to the first plurality of fuel cells until 100 percent of the target number of fuel cells is achieved and a target height is achieved, the second plurality of fuel cells being formed from one or more fuel cells from each the first, second and third groups of fuel cells; and affixing a second end plate to the first plurality of fuel cells and the first end plate thereby creating a fuel cell stack. ### Claim 17 (depends on 16) The method as defined in claim 16 wherein the step of selectively assembling the second plurality of fuel cells includes the step of measuring a remaining target height each time a new fuel cell is added to the second plurality of fuel cells.