SECONDARY BATTERY

PURPOSE:To prevent the generation of dendrite by arranging a magnetic field generating device which acts on the ion flow reaching the electrode plate surfaces. CONSTITUTION:Parmanent magnetic plates (N/S poles) 3, 4 are opposedly arranged such that they hold the space between a positive and negative electrode plates 1, 2 between them in the direction intersecting the opposing directions of the electrode plates 1, 2 so as to generate a magnetic field. The magnetic plates 3, 4 are also arranged such that the magnetic force G acts orthogonally on the ion flow reaching the surfaces of the plates 1, 2, i.e. the flow in/out current I. A force in the direction parallel to a small electrode plate, i.e. a small force for restraining the flow in the electrode plate, thus acts in responce to a small current, based on Fleming's left hand rule. If the strength of the magnets 3, 4 is properly selected, therefore precipitation of metal at the surfaces of the plates 3, 4 is uniformed so that the generation of dendrite is prevented. Consequently, the life of the secondary battery can be extended by preventing a short between the electrode plates due to the generation of dendrite.