Patent ID: 6569560
Filing Date: 2003-05-27
Classification: H01M,Y02E,Y02P

Abstract:
In a starved electrolyte battery; a container housing a plate stack of alternating positive and negative electrode plates with positive electrode leads joining the positive electrode plates of the plate stack to a positive battery terminal and negative electrode leads joining the negative electrode plates of the plate stack to a negative battery terminal; successive electrode plates of the electrode plates in the plate stack being spaced from each other a selected distance in the battery as assembled; the plate stack including first and second successive electrode plates; the first and second electrode plates each having first major surfaces facing each other and second major surfaces facing away from each other; the first and second electrode plates each having a peripheral edge intermediate the major surfaces of the electrode plate and extending completely about a perimeter of the electrode plate; the peripheral edges of the first and second electrode plates each having a length and a thickness; a first separator extending between the first major surfaces of the first and second electrode plates and separating the first and second electrode plates; a second separator overlaying the second major surface of the first electrode plate; a third separator overlaying the second major surface of the second electrode plate; an electrolyte absorbed in the first and second electrode plates and the first, second and third separators; the improvement comprising:the first, second and third separators being a resilient fibrous material; the first, second and third separators each having a peripheral edge extending completely about a perimeter of the separator; the peripheral edges of the first, second and third separators each having a length; and the first separator having an expanded portion, adjacent the peripheral edge of the first separator and extending the length of the peripheral edge of the first separator, that extends beyond the peripheral edges of the first and second electrode plates for the lengths of the peripheral edges of the first and second electrode plates; the second separator having an expanded portion, adjacent the peripheral edge of the second separator and extending the length of the peripheral edge of the second separator, that extends beyond the peripheral edge of the first electrode plate for the length of the peripheral edge of the first electrode plate; the third separator having an expanded portion, adjacent the peripheral edge of the third separator and extending the length of the peripheral edge of the third separator, that extends beyond the peripheral edge of the second electrode plate for the length of the peripheral edge of the second electrode plate; the expanded portion of the first separator extending beyond the peripheral edge of the first electrode plate and the expanded portion of the second separator extending beyond the peripheral edge of the first electrode plate distances sufficiently great to provide an amount of resilient fibrous separator material, beyond the peripheral edge of the first electrode plate and expanded in thickness due to the resiliency of the resilient fibrous separator material, so that the expanded portion of the first separator abuts the expanded portion of the second separator beyond the peripheral edge of the first electrode plate to completely encapsulate the peripheral edge of the first electrode plate for the length of the peripheral edge of the first electrode plate; the expanded portion of the first separator extending beyond the peripheral edge of the second electrode plate and the expanded portion of the third separator extending beyond the peripheral edge of the second electrode plate distances sufficiently great to provide an amount of resilient fibrous separator material, beyond the peripheral edge of the second electrode plate and expanded in thickness due to the resiliency of the resilient fibrous separator material, so that the expanded portion of the first separator abuts the expanded portion of the third separator beyond the peripheral edge of the second electrode plate to completely encapsulate the peripheral edge of the second electrode plate for the length of the peripheral edge of the second electrode plate.