Battery electrode fatigue simulator

• US 4,379,410 A
• Filed: 01/22/1981
• Issued: 04/12/1983
• Est. Priority Date: 01/22/1981
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Leonard, John F., Fritts, David H.
• Primary Examiner(s): Ciarlante, Anthony V.
• Assistant Examiner(s): Carlson, David V.
• Application Number:
  US06/227,565
• Time in Patent Office: 810 Days
• Field of Search: 73/808, 73/809, 73/810, 73/812, 73/813, 73/843, 73/893, 73/826, 73/828, 73/829, 73/830
• US Class Current: 73/809
• CPC Class Codes: G01N 2203/0016 Tensile or compressive
• CPC Class Codes: G01N 3/32 by applying repeated or pulsating forces

Abstract

A battery electrode fatigue simulator having a frame which supports therein a pivotal and a stationary beam. The pivotal and stationary beams secure therebetween an electrode plaque which is to undergo the fatigue simulation. Also mounted to the frame is a rotatable cam of predetermined dimension which acts upon a cam follower forming part of the pivotal beam thereby causing cyclic movement or displacement of the pivotal beam. This cyclic displacement is transferred to the plaque as a cyclic stress in tension. Measurements are made of the displacement of the pivotal beam as well as resistance of the plaque during the application of the cyclic stress. The cyclic displacement versus resistance relationship is representative of the fatigue a battery electrode will undergo during actual battery operation.

Claims

1. A battery electrode fatigue simulator comprising:

a frame;

a first support beam pivotally mounted at one end thereof to said frame and having a cam follower mounted at the other end thereof, said first support beam further having a plurality of notches situated therein, said notches being longitudinally displaced from each other with respect to the pivoting end of said first support beam, and means located in at least one of said notches for fixedly securing therein one end of an element which is to undergo fatigue simulation;

a second support beam adjustably secured at both ends thereof to said frame juxtaposed said first support beam, said second support beam having a plurality of notches therein oppositely disposed from said notches in said first support beam, and means located in at least one of said notches in said second support beam for fixedly securing the other end of said element therein;

a cam of preselected configuration rotatably mounted within said frame adjacent said cam follower, means operably connected to said cam for rotating said cam at a predetermined rate of speed, and means interconnected between said frame and said first support beam for constantly biasing said cam follower against said cam whereby rotational movement of said cam causes pivotal movement of said first support beam to take place in order to apply a predetermined cyclic stress to said element;

means secured to said frame juxtaposed said first support beam for determining the displacement of said first support beam at a plurality of locations along said first support beam, said locations being coincidental with said plurality of notches located in said first support beam in order to provide displacement information about said element during application of said cyclic stress; and

means operably connected between said element securing means in said first support beam and said element securing means in said second support beam for determining resistance in said element during the application of said cyclic stress;

whereby a relationship established between said displacement and said resistance is representative of battery electrode fatigue undergone during actual battery operation.

2. A battery electrode fatigue simulator as defined in claim 1 further comprising means situated in a plurality of said oppositely disposed notches for fixedly securing therebetween a plurality of elements, respectively, which are to undergo fatigue simulation.

3. A battery electrode fatigue simulator as defined in claim 1 wherein said resistance determining means comprises an ohmmeter.

4. A battery electrode fatigue simulator as defined in claim 3 wherein said displacement determining means is a transducer.

5. A battery electrode fatigue simulator as defined in claim 4 wherein said element is made up of electrode plaque.

6. A method of simulating the fatigue undergone by a plurality of electrodes during battery operation comprising the following steps:

(a) mounting a plurality of electrode plaques between a stationary support and a pivotal support, such that the plaques are longitudinally displaced from each other with respect to the pivoting end of said pivotal support;

(b) displacing said pivotal support in cyclic fashion in order to apply a cyclic stress in tension simultaneously to each of said electrode plaques;

(c) determining said cyclic displacement of said pivotal support during the application of said cyclic stress to said plaques;

(d) determining resistance in each of said plaques during application of said cyclic stress to said plaques; and

(e) establishing a relationship between said cyclic displacement and said resistance in each of said electrode plaques, said relationship being representative of battery electrode fatigue undergone during actual battery operation.