The “naturally degradable” battery
Nippon Telegraph and Telephone Corp (NTT) has developed a “naturally degradable” primary battery that does not do harm to soil or living organisms even when left in the natural world.
The electrode, electrolyte and casing (which usually have a high environmental load) of the battery are made of environmentally-friendly materials such as biological and fertilizer-derived materials. The output voltage of the battery is 1.1V (measured current: 1.91mA/cm2).
NTT said it expects that the battery will be used for sensor devices that are installed outdoors and cannot be easily retrieved.
The newly-developed battery is an air battery that uses oxygen in the air as a positive-electrode active material. In the positive (air) electrode of an air battery, there needs to be a three-dimensional conductive porous structure for diffusing oxygen contained in the air into the electrode.
Normally, the porous structure is formed by using fluororesin-based binding agent to solidify carbon powder. However, fluororesin generates toxic gas when burned, causing a high load on the environment.
NTT made it possible to form a porous structure without fluororesin binding agent by applying a certain process (of which the company did not disclose the details) to a biological material and carbonizing it.
The separator and the casing of the battery are also made of biological materials. For the negative electrode and electrolyte, NTT used materials that can work as fertilizers. But it did not disclosed the details of the negative electrode and electrolyte.
In a “plant damage test,” in which the used battery is crushed, mixed with soil and given to plants to see its influence on the plants, the company confirmed that the battery’s components remaining in the soil do not affect the growth of the plants.
One of the challenges in commercializing the battery is its electric capacity, which is about 1/10 that of a dry cell of an equivalent size.
“The battery can be improved in many ways such as electrode and electrolyte,” NTT said. “We want to increase its energy density to an equivalent level.”
Enjoy our free content ? Try our Legend services.
- Star Level
- Access to Grendz and the right to READ and SHARE our science techie green pins
- The right to WRITE and SHARE your OWN science techie green pins
- WEEKLY mind-blowing e-report with trends and news, never miss what is grendzing.
- Customization Capability on which trends categories you want us to follow closer.
- P2P Advice From our team and members
- Our iOS or Android app for free
- First to know about new trends and news
- Weekly social media promotions (through Grendz social media presence) of your own pins (tech, science, green related) that may include: Your own service, products, PR or/and business related
- No ads and no sales pitch
- 24h Support (via e-mail)
- Cancel anytime your renewal