According to Nikkei, Nippon Paper Industries has successfully lit a light bulb with a battery made from wood pulp, raising hopes for a future in which the use of drones, smartphones and electric vehicles will be eliminated. deplete rare metals.
Battery made from wood pulp, developed by Nippon Paper, does not use precious metals other than aluminum foil as electrodes
screenshot Takesaburo Takahashi
At Nippon Paper’s Fuji Innovative Materials Research Laboratory in Shizuoka Prefecture at the foot of Mount Fuji in late November 2021, a small light bulb emitted a strong light when connected to a battery made of wood pulp. Although the light lasted only three seconds before it began to dim, the head of the laboratory, Fuminari Nonomura, called it a “revolutionary” moment. The wood pulp battery is made of cellulose nanofibers 3 nanometers (nm) in diameter, 0.05 mm thick, and weighs 0.15 grams. The nanofibers are purified from wood pulp, then processed into thin films separated by aluminum foil, which act as an electrode.
These nanofibers can store and release electricity as is the case with metal batteries. However, unlike today’s lithium-ion batteries, it does not degrade, not even after millions of charges and discharges. This particular property was discovered in March 2021 by researchers at the Fuji lab, which Nippon Paper co-runs with Mikio Fukuhara, a researcher at Tohoku University, and others.
While a 3 Volt (V), 0.025 amp LED bulb stays on for 7 seconds, the energy density or energy storage capacity of a wood pulp battery measures about 1 watt-hour/kilogram. In a previous experiment, Fuji researchers recorded power densities of up to 10 watt-hours. In these two experiments, the capacity of wood pulp batteries was shown to be equivalent to one part 200 and one part 20 of a lithium-ion battery.
In Nippon Paper’s latest test, the bulb stayed on for 7 seconds or so, but the company expects to be able to increase the battery capacity to a level that can power drones by fiscal 2023. , followed by smartphones and other devices by fiscal year 2030. The Japanese paper maker also wants to install wood pulp batteries in cars. If successful, Nippon Paper’s innovation will be a turning point, helping to reduce dependence on rare metals.
The price of lithium has more than doubled in the past year to about $30/kg. Cobalt prices also doubled to $60,000/ton. The Democratic Republic of the Congo is estimated to account for 70% of the world’s cobalt production, while more than 20% of nickel is produced in China. As the use of electric vehicles increases, the reduction of rare metals will become increasingly urgent because their use creates economic security concerns.
Nippon’s wood pulp batteries can be obtained from the forests of Japan, and can potentially be replenished by planting trees. The company’s main challenge now is to dramatically improve the battery’s storage capacity before it can power electric vehicles.
According to Nikkei, Nippon is looking to increase battery capacity by overlapping cellulose nanofiber membranes. The company also needs to develop technology to process the nanofibers into sheets of equal thickness to prevent them from burning. It should also join hands with other battery and device makers to develop those technologies.
“Research on new materials will not create the next source of income for Nippon Paper any time soon,” said an analyst at the Japanese securities firm. However, according to Mikio Fukuhara, as a paper manufacturer, Nippon Paper will pave the way for “paper electronics” that can contribute to carbon removal.