Patent ID: 8343669

Claim:
An electrochemical device comprising: an electrode matrix including a multilayer structure laminating positive and negative electrodes with a first separator interposed therebetween; and first and second dummy electrodes respectively arranged on both end faces in the laminating direction of the electrode matrix; wherein one of the first and second dummy electrodes and the other are electrically connected to the positive and negative electrodes in the electrode matrix, respectively; wherein the first and second dummy electrodes have respective opposing parts opposing each other through a second separator at an outer peripheral part of the electrode matrix; wherein within the outer peripheral part of the electrode matrix, the first and second dummy electrodes do not oppose each other through the first separator; wherein one or each of the first and second dummy electrodes has a resistance control layer at least on a side where the opposing parts oppose each other; wherein the resistance control layer has a resistance value as a total resistance value of the first and second dummy electrodes falling in such a range that an estimated internal short circuit current between the first and second dummy electrodes is equivalent to 0.09 C to 1.00 C; and wherein the first and second dummy electrodes opposing each other through the second separator are adapted to short-circuit each other at a lower temperature than the positive and negative electrodes opposing each other through the first separator in the electrode matrix do.