both primary and secondary ones are batteries that are designed to be conformal and flexible, while the traditional batteries are rigid with certain shapes. The increasing interest in portable and flexible electronics has led to the development of flexible batteries which can be implemented in products such as smart cards, wearable electronics, novelty packaging as well as flexible displays and transdermal drug delivery patches.[1][2] Hence efforts are underway to make different flexible power sources including primary and rechargeable batteries.
Disposable, primary flexible primary batteries which are the equivalent of AA and AAA batteries are also of great interest with applicability in smart cards, medical patches, greeting cards, toys, and disposable devices. Advantages of primary batteries with aqueous electrolyte over lithium ion batteries include their eco friendliness and the ease of fabrication. A flexible zinc-carbon battery using single-walled carbon nanotubes as current was reported by Hiraral in 2010;[10] later in 2013 one with conductive polymer and cheaper multiwalled carbon nanotubes was published by Mitra. Et. al.[11] Binders were used to maintain the flexibility and integrity of electrodes, and the carbon nanotubes dramatically reduced electrode resistance. The primary alkaline battery is more durable than conventional zinc-carbon under heavy load. An alkaline battery uses MnO2 as the active material along with zinc anode and KOH is used as an electrolyte here. A flexible alkaline cell offers several challenges because compared to zinc-carbon cells using weak acidic or neutral electrolytes, KOH is more basic and corrosive. Gaikwad first proposed an alkaline battery using nylon mesh [12][13] and more recently Wang and Mitra [14] reported an alkaline cell using. A rechargeable flexible alkaline battery has also been reported by the same group.[15]