Researchers at Australia’s RMIT University in Melbourne say that, after many years of intensive research, they have created a battery that uses a carbon electrode, water, and a permeable membrane to store electricity. The research is funded by the Australian Defense Science and Technology Group and the US Office of Naval Research Global.
“Our latest advance is a crucial step towards cheap, sustainable proton batteries that can help meet our future energy needs without further damaging our already fragile environment. As the world moves towards inherently variable renewable energy to reduce greenhouse emissions and tackle climate change, requirements for electrical energy storage will be gargantuan.
“The proton battery is one among many potential contributors towards meeting this enormous demand for energy storage. Powering batteries with protons has the potential to be more economical than using lithium ions, which are made from scare resources. Carbon, which is the primary resource used in our proton battery, is abundant and cheap compared to both metal hydrogen storage alloys and the lithium needed for rechargeable lithium ion batteries.”
“Future work will now focus on further improving performance and energy density through use of atomically-thin layered carbon based materials such as graphene, with the target of a proton battery that is truly competitive with lithium ion batteries firmly in sight,” Andrews says.
According to Science Daily, “The working prototype proton battery combines the best aspects of hydrogen fuel cells and battery-based electrical power. The latest version combines a carbon electrode for solid-state storage of hydrogen with a reversible fuel cell to provide an integrated rechargeable unit.”
“During charging, protons produced by water splitting in a reversible fuel cell are conducted through the cell membrane and directly bond with the storage material with the aid of electrons supplied by the applied voltage, without forming hydrogen gas. In electricity supply mode, this process is reversed. Hydrogen atoms are released from the storage [medium] and lose an electron to become protons once again. These protons then pass back through the cell membrane where they combine with oxygen and electrons from the external circuit to re-form water.
“A major potential advantage of the proton battery is much higher energy efficiency than conventional hydrogen systems, making it comparable to lithium ion batteries. The losses associated with hydrogen gas evolution and splitting back into protons are eliminated.”
The original research has been published in the International Journal of Hydrogen Energybut is hidden behind a pay wall; hence the extensive quotes from Science Daily.
The proton battery was the subject of research at RIMT several years ago, but used a metal alloy electrode containing rare earth elements. The resulting device was heavy and expensive and it worked poorly in terms of reversibility and rechageability. The latest version using carbon and water is able to store the same amount of energy per unit of weight as a conventional lithium ion battery at 1.2 volts.