IDEA #2VHJKI Technique for embedding electrochemical material in a conductive fabric for a stretchable/flexible power source application. 12A0051

This invention shows a technique to make stretchable/ flexible battery electrode by embedding the electroactive materials inside a fibrous current collector (silver cloth) with a self-assemble of electroactive ink driven by capillary force. These electrodes can then be used to form a complete alkaline battery, which can be flexed, twisted and stretched up to 100 % without any drop in capacity. Flexible, stretchable and wearable devices require a battery to power them with similar form factor. In our previous published work we should a technique to make a high flexible battery by embedding the electroactive material inside a nylon/metal mesh (U.S. Ser. No.: 13/095,373). The mesh acts as a support and prevents cracking/delamination when flexible. This technique is limited to flexible electrodes and cannot be used for stretchable electrodes. A stretchable battery electrode requires a stretchable current collector, which should maintain a high electronic conductivity even after large number of stretch cycle and the electroactive ink in contact with the current collector should not delaminate on stretching. This can be achieved if the current collector and the electroactive material experience no stress on stretching. Our technique of making a stretchable battery electrode is based on a commercially available silver coated nylon fiber based stretchable fabric, which is used as a current collector. The silver fabric can be used as current collector for battery application due to it high conductivity and high crease resistance. Our invention is the technique to coat the silver cloth with electroactive materials such that no delamination/ disintegration of electrode takes place on flexing. Due to the weave pattern of the cloth the silver coated on nylon string experiences no stress of stretching. We make a carefully designed dilute electroactive ink with binder, additives and electroactive materials. The fabric is soaked inside the electroactive and the electroactive particles are then self-assembled inside/on the fibrous structure of the cloth and the excess of ink is removed. This technique ensures that the ink is only inside the bunch of silver fibers. Due to the weave pattern of the silver cloth the electroactive ink will experience no stress on flex/stretch.