Patent ID: 6635381
Filing Date: 2003-10-21
Classification: H01M,Y02E,Y02P,Y10T

Abstract:
A secondary electrochemical cell, which comprises:a) a casing; b) a unitary negative electrode comprising at least three negative plates, each having spaced apart first and second major sides joined by a negative peripheral edge, wherein the first and second major sides are contacted with a negative electrode active material that intercalates with an alkali metal, and wherein the negative plates are connected together by negative connecting portions; c) a unitary positive electrode comprising at least two positive plates, each having spaced apart third and fourth major sides joined by a positive peripheral edge, wherein the third and fourth major sides are contacted with a positive electrode active material that intercalates with the alkali metal, and wherein the positive plates are connected together by a positive connecting portion; d) a separator disposed between the negative electrode and the positive electrode; e) wherein the negative electrode and positive electrode are electrochemically associated with each other as an electrode assembly housed in the casing to provide the positive plates interleaved between the negative plates with one of the negative plates disposed immediately adjacent to the opposite third and fourth major sides of the two positive plates, and wherein the positive peripheral edges of each positive plate are completely bounded by the negative peripheral edges of the immediately adjacent negative plates to prevent alkali metal from plating as the cell is repeatedly cycled between a charged and a discharged condition, and wherein the negative plates are sized such that in the electrode assembly an intermediate second negative plate has a larger periphery than both a first and third negative plates opposite the first and second major sides of the second negative plate; and f) an electrolyte solution activating the negative and positive electrodes.