A New Material for Lithium Batteries

Ohara has developed a flexible sheet used as an electrolyte in lithium batteries.

In rolls of 150 mm wide sheet of 50 micron thickness is made from an organic polymer and a ceramic glass powder with a high lithium ion conductivity.

The material is manufactured as a thin film to be used in different types of sensors and also the form of powder particles of 1 to 10 microns.

Lithium battery for many current has a liquid electrolyte. The transition to the solid electrolyte according to the company would enhance the safety of batteries.

It remains to improve the characteristics of the flexible sheet to be able to find applications in smart cards and other electronic devices.

Different Batteries for Different Uses

Handheld devices (clocks, watches, cameras, MP3 players ...) are powered by batteries. Each battery is designed for a particular purpose.

Battery saline
It is the oldest and least expensive batteries, but also less efficient.
The reagents consumed and releasing energy during operation, are manganese dioxides and zinc metal. This cell also contains ammonium chloride described as "salt", hence the name given to this type of battery.
This battery supplies a voltage of 1.5 V. It is used for less demanding applications (alarm clocks, toys ...), because its lifetime is relatively short.

The alkaline battery
This battery, almost the same constitution as a battery saline contains more potassium hydroxide. Potassium is a metal of the family of alkaline, hence the name given to this type of battery.
This battery also delivers a voltage of 1.5 V. It can provide higher currents as the battery and salt for longer. So should she uses most demanding digital cameras, MP3 players ...
Alkaline battery is on average twice as expensive than salt pile.

The lithium battery
This lithium battery, at equal volume, far more power than its predecessors, but it is even more expensive. The reagents are lithium metal (replacing zinc) and various metal oxides. According to the oxide used, the terminal voltage is different (from 1.2 V to 3.5 V).
It is used in flat calculator for other uses long-term low intensity such as watches, tools heart ...
Cells facing recycling
Every year in France, almost 29 000 tons of batteries, or nearly one billion units, are used. If we add the batteries, there are thousands of tons of heavy metals such as zinc, manganese, cadmium, nickel, lead and mercury that should prevent the release into the environment as they are dangerous to health.
Accumulate in living organisms, animals or plants, they can cause poisoning and serious diseases, it is necessary to prevent contamination of soil and groundwater. For this, one answer: the recovery and recycling.
Since 1999, it is forbidden to dispose of li-ion battery with the rest of the garbage. However, too many people are unaware of and specific collection bins are not always easily accessible. The result is that in France, we collected only 31% of batteries consumed, in which 45% of metals are not recycled because of technical difficulties.

Advantages and Disadvantage of Lithium-ion Batteries

Lithium-ion batteries have a high energy density for a very low weight, thanks to the physical properties of lithium (very good weight/ electric potential).These batteries are widely used in embedded systems.They have no memory effect unlike ni-mh battery.

They have a low self-discharge (10% per month and often within a few per year!).
No maintenance
Provide better security than pure lithium battery, but still require a protection circuit.

Weaknesses of lithium-ion batteries

They are aging more slowly when they are partially recharged, until they experience complete cycles of charge / discharge.
On consumer products, this technique is aging even when not in use ( from internal corrosion and increasing internal resistance)
The current charge and discharge are eligible lower than with other techniques.
There may be a short circuit between two electrodes by dendrite growth of lithium.
Liquid electrolyte is dangerous if a leak occurs and it is exposed to air or water.
This technique has misused the potential dangers: they can be degraded by heating beyond 80 ° C in a backlash and dangerous.

Always handle the li-ion batteries with extreme care. Li-ion can be explosive. Moreover, as with any battery: never to short circuit the battery, reverse polarity, overload or break the case.

To avoid problems, these batteries must always be equipped with a protection circuit, a control circuit (the BMS Battery Management System), a thermal fuse and a relief valve. They must be charged in accordance with very specific parameters and never be discharged below 2.5 V per cell.

Several manufacturers such as Fujitsu-Siemens and Nokia have launched an exchange program for batteries due to overheating problems on some batteries they sold.

FUJIFILM HS25EXR AND HS30EXR

Fujifilm today announced the expansion of its range of HS bridges with two new models: the FinePix FinePix HS25EXR and HS30EXR. These two new devices come to the estate of Fujifilm FinePix HS20EXR.

Equipped with a CMOS sensor EXR 16 megapixel and a Fujinon 30x (24-720mm), the FinePix?? HS25EXR HS30EXR and has a 3-inch LCD screen, with a mode sun, s' adjust the brightness, especially in strong sunlight. Finally, on their commonalities, an intelligent digital zoom and a manual focus for the video will expand the list of characteristics of these new FinePix. The new HS series cameras can also shoot in Full HD 1080p.

Finally, the HS30EXR differs from HS25EXR by a rechargeable battery with a range of about 600 photos, while the HS25ERX will in turn powered by four AA batteries for a range of 350 photos. Furthermore, different modes will be programmable on HS30EXR and it will carry the RAW format, unlike the HS25EXR.

The HS30EXR should be available in early March to € 449.90, while the HS25EXR will be sold only from late April to € 349.90.

Prototypes of backup power are emerging

On the occasion of the exhibition "Eco-Products 2011" held in Tokyo from 15 to 17 December 2011, the Japanese company Sharp exhibited a prototype storage unit residential electricity, using lithium-ion battery (Li-ion battery).
The storage unit "SunVista" may be charged with excess electricity produced by photovoltaic panels (PV) or simply by the current power grid. This device is primarily intended for use as a source of backup power supply when the main system fails.
While Sharp has not yet set the price and the release date of his storage unit, it seems that the ability of the prototype is about 5 kWh. "Whereas it is used at home, the ability to 5kWh remains appropriate," said the company.
In addition, Sharp is still trying to determine whether it will operate as a device, the Lithium batteries manufactured in-house or not. It then estimates the storage units will be sold primarily to households with photovoltaic panels.
Similarly, the competitor Kyocera Solar presented a prototype of "Solar-UPS" (pictured above), a storage unit for residential electricity can be used with photovoltaic panels. The system was developed in collaboration with Sanken Electric.
As for Sharp, Solar-UPS is designed to be used primarily as a power supply in case of power failure. The unit would be programmed to recover about 20% of the electricity generated by photovoltaic solar panels.
The ability of rated power and storage capacity of the main unit of "Solar-UPS" are respectively 3kVA / 2.1 kW and 333 Wh. And since the device operates as a UPS backup battery power (uninterruptible power supply), it is possible to go directly to the solar inverter without power interruption in case of power failure.
Up to three modules of energy storage (up to 2.1 kWh) can be connected to the network. It takes about 12 hours to fully charge the main unit. But the load time depends greatly on the design of photovoltaic panels connected to the unit. Kyocera Solar has yet to disclose pricing or a possible release date.