Abstract: A lithium cell and method for producing, wherein an electrode contains a first polymer and a separator contains a second polymer having a melting point below that of the first polymer. The first polymer may be the same in the anode and the cathode, or one electrode may contain the first polymer and the other electrode contain a third polymer. The first polymer may be a homopolymer, and the second polymer may be a copolymer, and may contain the first and/or third polymers as components. In one embodiment, the first polymer is polyvinylidene fluoride (PVDF) and the second polymer is PVDF and hexafluoropropylene. The relatively high melting point first and/or first and third polymer(s) permits high temperature drying of the electrodes, which facilitates water removal and thereby increases cell life. It also reduces swelling of the porous structure, which facilitates permeation of the electrolyte.
Abstract: A charging strategy for a rechargeable battery pack is disclosed. The battery pack is used in an application that includes a dynamoelectric machine that may operate as a motor, drawing power from the battery pack, or as a generator, delivering regenerative energy to the battery pack. The strategy monitors the nature, intensity, duration and frequency, among other things, associated with encountered episodes of regenerative energy from the dynamoelectric machine, and adjusts subsequent recharging processes to allow a calculated amount of headroom to accommodate regenerative energy inputs in the future, which may be assumed to be equal in nature, intensity, duration and frequency to what has already been observed. Overcharging is reduced or eliminated, while maximizing the amount of charge on the battery pack, and thus duration of use.
Abstract: The present invention, a cell layer edge support, provides longer battery cell life while minimizing the possibility of shorts within the cell. More specifically, an edge support layer is positioned around at least a portion of the smaller electrode, either the anode or the cathode, in the cell to define a supporting perimeter comparable to the perimeter of the larger electrode. The support layer generally comprises a polymeric material which helps to absorb pressures exerted on the cell layers during packaging. The anode, cathode, support layer and a separator layer placed between the anode and the cathode may be joined to form a battery. Preferably, a plurality of cells having the support layer may be joined to form a higher energy, longer life battery.
Type:
Grant
Filed:
September 6, 2002
Date of Patent:
September 20, 2005
Assignee:
Enerdel, Inc.
Inventors:
Dell Albert Crouch, Jr., Gregory K. Maclean
Abstract: A battery pack containing a plurality of battery modules, said modules comprising a plurality of individual battery units, said battery units comprising a plurality of bicells with opposing terminals. The battery modules are connected in series by use of a flexible circuit and by opposing positive and negative terminals of each battery unit. The terminals of each battery unit contain a region of apertures which allow the adhesive of the packaging material to seal more effectively, thereby eliminating or reducing the amount of leakage from an individual battery unit.