The Mercury is becoming a disliked material across the
industry for its hazardous properties to the bio on earth.
Due to no availability of replacement material for Mercury
particularly in alkaline batteries, it's still getting into
batteries. However, Sony has successfully able to make the
alkaline battery without this killer metal.
Sony has announced the realization of a mercury-free alkaline
button battery (LR), and plans to commercialize six models
of those environmentally conscious batteries.
With conventional alkaline button batteries, mercury was
added to the anode material in order to prevent the occurrence
of Hydrogen gas. Furthermore, as the cathode material used
in these batteries was known to have a low rate of Hydrogen
gas absorption, making the creation of a totally mercury-free
alkaline button battery a significant technological challenge.
The new mercury-free alkaline button incorporates proprietary
Sony technology that mixes absorbent raw material into the
cathode for the first time. By combining this with existing
technology that prevents Hydrogen gas occurrence on the
anode (which Sony originally adopted in its mercury-free
silver oxide (SR) button batteries), Sony has succeeded
in eliminating the use of mercury in these new batteries.
Three countermeasures used by Sony to control Hydrogen gas
emissions are:
1. Adoption of high quality Zinc alloy powder with improved
resistance to corrosion
2. Addition of anti-corrosion material into anode materials
3. Adoption of anti-corrosion technology in the collector
materials
Sony's sales of alkaline button batteries and sliver oxide
button batteries total approximately 300 million per year.
The development of a new mercury-free alkaline button battery,
in addition to Sony's existing silver oxide button batteries,
will result in a reduction of approximately 470kg and approximately
68 bottles (500ml per bottle) of mercury per year2. In general,
when mercury is not disposed properly, it can infiltrate
the food chain, and mercury has therefore been identified
as a material that has of the potential to cause serious
damage to the human body and environment.
The mercury-free models specs, price and availability
| Model Name |
Size |
Voltage |
Launch Date |
Price |
| LR44-ECO |
11.6 x 5.4 |
1.5V |
Oct.10th, 2009 |
200 JPY |
| LR43-ECO |
11.6 x 4.2 |
1.5V |
Oct.10th, 2009 |
200 JPY |
| LR41-ECO |
7.9 x 3.6 |
1.5V |
Oct.10th, 2009 |
200 JPY |
| LR1130-ECO |
11.6 x 3.05 |
1.5V |
Oct.10th, 2009 |
200 JPY |
| LR1120-ECO |
11.6 x 2.05 |
1.5V |
Oct.10th, 2009 |
200 JPY |
| LR44-2ECO |
11.6 x 5.4 |
1.5V |
Oct.10th, 2009 |
400 JPY |
Together with the realization of this mercury-free alkaline
button battery, Sony also introduced a new package design
for its mercury-free alkaline button batteries and mercury-free
silver oxide button batteries, and will launch them as its
"mercury-free series".
The function of mercury in conventional alkaline button
batteries:
Alkaline button batteries use Zinc for their anode, manganese
dioxide as the cathode, and an alkaline electrolyte. Zinc,
which is the activator in the anode, corrodes when dissolved
in alkaline solution. When this happens, it becomes difficult
to maintain the capacity of the unused battery. Zinc also
causes electrolysis in the electrolyte, generating Hydrogen
gas which causes increased inner pressure and expansion
of the cell. For this reason, mercury, which is effective
in suppressing Zinc corrosion, was added to the battery.
