Batteries power a wide range of electronic devices including phones, laptop computers and medical devices such as cardiac pacemakers andDefibrillators. In the near future, batteries may also help fight global warming by improving the performance of electric or hybrid vehicles with zero or reduced carbon emissions. With the ever increasing demand for efficiency and design, there is a need for ultra thin, safe and flexible energy storage options. Power sources are needed for the operation of the paper electronics, and ideally, a power source directly integrated onto paper would be preferred for easy system integrationsThere is a strong interest in thin, flexible energy storage devices to meet modern society needs for applications such as interactive packaging, radio frequency sensing, and consumer products. In this article, we report a new structure of thin, flexible Li-ion batteries using paper as separators and free-standing carbon nanotube thin films as both current collectors. The current collectors and Li-ion battery materials are integrated onto a single sheet of paper through a lamination process. The paper functions as both a mechanical substrate and separator membrane with lower impedance than commercial separators. The CNT film functions as a current collector for both the anode and the cathode with a low sheet resistance (_5 Ohm/sq), lightweight (_0.2 mg/ cm2), and excellent flexibility. After packaging, the rechargeable Li-ion paper battery, despite being thin (_300 _m), exhibits robust mechanical flexibility and a high energy density (108 mWh/g). These devices can be paper thin, flexible, lightweight and manufactured by a low cost, roll-to-roll printing process.Paper batteries are Flexible, ultra-thin energy storage and production device, Formed by combining carbon nanotubes with a conventional sheet of cellulose-based paper. A paper battery acts as both a high-energy battery and super capacitor .This combination allows the battery to provide both long-term, steady power production and bursts of energy. These thin batteries can be folded, cut or otherwise shaped for different applications without any loss of efficiency. Cutting one in half , halves its energy production. These Can be stacked in multiples of power output.