APPLICATION NOTES

MicroEnergy Cells
microenergy-banner

Brief Description:

IPS' innovative THINERGY® Micro-Energy Cells (MECs) are revolutionary solid-state, rechargeable, energy storage solutions that serve a variety of vertical markets. These paper-thin MECs are flexible and provide unrivaled cycle life and power performance. Able to operate in temperatures ranging from -40ºC to +85ºC, these ultra-thin MECs offer extremely low self discharge rates, low cell resistance and high power-making THINERGY the industry leading micro-energy storage offering. THINERGY Micro-Energy Cells are ideally suited for use with all forms of ambient energy harvesting techniques for recharging-such as solar, thermal, RF, magnetic and vibration energy-delivering a safe, reusable and clean power source for today's electronic devices and systems.

The rechargeability feature of the THINERGY MEC is critical for many applications. Just like an automobile that only carries around the amount of fuel needed for a certain amount of use (usage duty cycle), a rechargeable battery allows an application to only carry the amount of energy needed for its usage duty cycle - then it can be recharged and used over and over again. This allows for a much smaller, thinner, and lighter device design.

THINERGY MECs can be recharged beyond 100,000 cycles, making them perfect for trickle charge (constant recharge) applications, such as when used as a backup battery or when integrated with energy harvesting circuits. Re-charge takes only a few seconds to a few minutes, depending on the state of discharge. There is no "memory" effect, so a full discharge and recharge is not necessary to prolong the capacity life of the battery.

There are several charging methods to Charge THINERGY:

  • The batteries can be recharged in several different ways including:
  • Infrastructure/Direct wire re-charge - Use of a direct electrical connection of the MEC to a re-charge circuit
    (conventional method used to re-charge batteries)
  • Inductive re-charge - Use of a magnetic field to wirelessly induce a current into a receiving coil with a control circuit that
    is connected to the battery
  • Energy Harvesting solutions such as:
  • Solar/Photovoltaics (converting light energy)
  • RF (Converting stray or directed radio frequency energy)
  • Kinetic (Converting vibrational energy)
  • Thermoelectric (Converting changes in heat energy)

The energy harvesting solutions provide a continuous, autonomous power source that, depending on the design, may provide a sufficient trickle charge to the battery such that a conventional direct wire recharge may never be needed, allowing decades of power without battery replacement. Leveraging it's revolutionary thinness, superior pulse power, and unrivaled cycle life, THINERGY® Micro Energy Cells deliver a superior energy storage solution to a wide range of markets.

APPLICATIONS: Energy Harvesting:

An IPS MEC is superior in their charge acceptance and ability to efficiently store energy harvested from ambient environments such as radio frequency, magnetic, solar, heat and vibration. System designers utilizing our new THINERGY Applications Development Platform (ADP) will be able to evaluate both the performance of our revolutionary micro energy cells (MECs) along with a variety of third-party ambient energy harvesting systems.

Autonomous Wireless Sensors:

The ideal wireless sensor node (WSN) is small and lightweight, has sufficient power for accurate sensor readings and processing capability, can reliably transmit over useful distances, and is able to operate autonomously with zero maintenance for the life of the application. The number one inhibitor to achieving each of these ideal characteristics is the power source. Conventional batteries with organic liquid or polymer electrolytes only last a few years, and are very bulky. Supercapacitors have more than sufficient pulse power, but suffer from poor energy density and have very high leakage currents. Because supercaps hold so little energy, each data transmission of a WSN consumes a significant percentage of the supercap's energy, which is counted as a "cycle." If a sensor transmits every second, the supercap must cycle approximately 30,000,000 times in just one year.

THINERGY MECs are fundamentally different and provide the best solution for each of the wireless sensor node challenges. An MEC typically smaller than the devices they power, so they do not define the system form factor like other batteries or supercaps. As the world's most powerful battery for its size, MECs are unrivaled in their ability to provide high pulse current combined with ample energy density in a single device. Therefore, they can power the entire WSN (sensor, µP, radio, etc.), without the aid of additional capacitors, for days, weeks or months, on a single charge, depending on the duty cycle. When combined with ambient energy harvesting and IPS' patent-pending Passive Power Management Unit (PPMU™) electronics, a postage stamp sized MEC can autonomously power a WSN for decades. With their unprecedented cycle life of >10,000 full depth recharge cycles, and >100,000 shallow discharge cycles, the MEC will typically outlive the application it is powering. Since the capacity of the cell is so much higher than a supercap, typical transmit cycle of a WSN radio chip takes only about 0.002% of the energy of the cell. It takes about 40,000 transmit events of a typical WSN to be counted as a "cycle", which means the MEC can typically survive >400,000,000 transmit events, from a single MEC101-type cell. Stacking cells (electrically connected in parallel) further increases the capacity without increasing the footprint, and further increases the number of transmit events that can be performed on a single charge, and the cycle life of the device. With their all solid-state construction and inorganic electrolyte, THINERGY Micro Energy Cells have a typical self discharge rate of (10nA, operate over an extremely broad temperature range (-40°C to +85°C), and offer decades of maintenance-free service life for all forms of wireless sensor nodes. The ideal battery for the ideal WSN has arrived.

Powered Cards:

Powered Cards represent a rapidly growing application space for any micro-electronic solution in the shape of a credit card. The functionality goes beyond the traditional bank card with display or biometric authentication, and now includes customer loyalty cards, driver's licenses, medical cards, wireless sensor nodes and many other applications. Traditionally, these cards have been powered with thin, flexible primary (non-rechargeable) batteries. These cells offer a lifetime energy of around 12-25mAh, but deliver only low currents, which limit the potential functionality of the card. When the energy is used up, usually in less than 2 yrs (or sooner with added functionality), the entire card must be discarded and replaced - and at a significant expense just because the conventional battery "died. "THINERGY MECs offer a superior solution for powered card applications due to their unprecedented power, long life, and rapid rechargeability. The MEC can be hot laminated and has sufficient power to run a 32-bit ARM core processor within the card, which is sometimes needed to achieve rapid match-on-card biometric authentication. THINERGY MECs can be recharged "autonomously" via integrated energy harvesting, such as Piezo films, RF antennas and flexible photovoltaics. In addition, each time the card is "read" using Near Field Communications (NFC), which is like a passive RFID event, the 13.56MHz RF energy can be harvested to put power back into the MEC (data out, power in). This effortless recharge method leverages the existing RF reader infrastructure around the globe for NFC bank card Point of Sale (POS) readers, security systems with physical access doorway readers, or automotive keyless entry systems. THINERGY MECs allow designers to add power consuming features to powered cards, such as biometrics, displays, GPS data-loggers, wireless sensors and transmitters, without shortening the life of the battery or the card because the MEC can simply be recharged. In essence, THINERGY MECs last the life of the card.

Active RFID/RTLS:

THINERGY MECs can be used in a wide range of RFID Applications including - Security & Asset Control Tags, Smart Labels, Flexible RFID Tags Integrating a THINERGY Micro-Energy Cell into an active RFID application will:

  • Provide increased range, power and data transfer speed
  • Increase the useful lifetime of the tag
  • Allow re-charging and re-use of the tags
  • Rechargeable using RF, inductive, or ambient energy field
  • Increase the operating temperature range of the tag
  • Allow for thinner/flexible product packaging

Medical Devices:

A THINERGY MEC can be used in a wide range of medical devices including - Implantable Devices, Hearing Aids, Glucose Monitors, Drug Delivery Systems, Pacemakers and implantable insulin pumps. THINERGY MECs provide the highest energy density package with virtually limitless lifetime performance in a safe, solid-state package that can be implanted for life and recharged unobtrusively within the body with non-invasive RF energy, and:

  • provide continuous power or back-up power
  • limit the need for battery replacement and patient surgeries
  • enable smaller, thinner devices
  • can be recharged unobtrusively through the body

The high pulse current capability reduces need for additional components such as charging capacitors. Contact IPS to discuss your specific medical application.

Memory and RTC Backup Power:

THINERGY MECs can power many RTC chips from major manufacturers such as EM Microelectronics, Epson, Intersil, Maxim, OKI Semiconductor, and Texas Instruments (TI). For certain system applications, specialized circuitry can enable the THINERGY MEC to fully power RTC chips and allow read/write cycles, even when main power is disabled. Other micro-battery backup power solutions have insufficient discharge current and do not allow read/write cycles during system black-out periods.

In addition, these solid state, rechargeable, thin film Micro Energy Cells are the ideal micro-battery backup power solution source for SRAM memory ICs. MECs feature class-leading low self-discharge currents allowing charge retention for decades and provide a flat output voltage of 4V. They can be trickle charged with an unlimited number of charge and discharge cycles. THINERGY MECs provide back-up power to a wide variety of SRAM chips from manufacturers such as Cypress, Dallas Semi/Maxim, Micron, Renesas, Samsung, and Texas Instruments.

THINERGY MECs charge from zero to 90% capacity in only 10 minutes. The recharge is simple from a regulated 4.1V source and there are no external current limiting components. MECs are much smaller than coin cell batteries and super capacitors, and provide backup power for up to 20 times longer than other thin film batteries. Estimated backup times range from weeks to months.

Military / DOD:

THINERGY MECs offer a compelling micro-battery backup pwer solution for Military/DOD applications due to their incredible power density, shock resistance, broad operating temperature range (-40°C to +85°C), and greater than 10 year life. They can be stacked into battery modules that can deliver, for example, 1 Amp of continuous current at 25°C in a compact module only 26mm x 26mm x 3.5mm. MECs can replace expensive "Reserve" batteries since they are much smaller, provide instant-on power, and can be stored in bunkers for decades while still maintaining their charge. Applications include:

  • Unmanned Aerial Vehicles (UAVs)
  • Smart Weapons/Bullets
  • Self-Destruct Fuzes
  • Communication Devices
  • Wireless Sensors
  • Active RFID/RTLS Tags
  • High Temperature Applications up to 200°C for Short Durations

THINERGY MECs are essentially a hybrid solution that leverages the energy density of batteries with the high discharge current of supercaps. Combined with less than 10nA of leakage current

Manufacturer:

Infinite power Solution (www.infinitepowersolutions.com)