Quantum Phase Battery...

The first quantum phase battery, consisting of an indium arsenide (InAs) nanowire in contact with aluminium superconducting leads. (Courtesy: Andrea Iorio)

Topics: Battery, Cooper Pairs, Materials Science, Quantum Mechanics, Superconductivity

Researchers in Spain and Italy have constructed the first-ever quantum phase battery – a device that maintains a phase difference between two points in a superconducting circuit. The battery, which consists of an indium arsenide (InAs) nanowire in contact with aluminium (Al) superconducting leads, could be used in quantum computing circuits. It might also find applications in magnetometry and highly sensitive detectors based on superconductors.

In a classical battery (also known as the Volta pile), chemical energy is converted into a voltage difference. The resulting current flow can then be used to power electronic circuits. In quantum circuits and devices based on superconducting materials, however, current may flow without an applied external voltage, thus dispensing with the need for a classical battery.

The concept of a quantum phase battery was studied theoretically in 2015 by Sebastián Bergeret of the Material Physics Center (CFM-CSIC) and Ilya Tokatly at the University of the Basque Country in Donostia-San Sebastián, Spain. Their battery design comprised a combination of superconducting and magnetic materials and was based on a Josephson junction – a non-superconducting region through which the Cooper pairs responsible for superconductivity can tunnel. This semiconducting “weak link” provides a persistent phase difference between the superconductors in the circuit, similar to the way that a classical battery provides a persistent voltage drop in an electronic circuit. Thanks to this phase difference, a superconducting current (that is, a current with zero dissipation) flows when the junction is embedded in the superconducting circuit.

Physicists create quantum phase battery, Isabelle Dumé, Physics World

Batteries, Diamonds and Nanothreads...

Next big thing:
Haifei Zhan and colleagues reckon that carbon nanothreads have a future in energy storage.
(Courtesy: Queensland University of Technology)
Topics: Applied Physics, Battery, Materials Science, Nanotechnology
Computational and theoretical studies of diamond-like carbon nanothreads suggest that they could provide an alternative to batteries by storing energy in a strained mechanical system. The team behind the research says that nanothread devices could power electronics and help with the shift towards renewable sources of energy.
The traditional go-to device for energy storage is the electrochemical battery, which predates even the widespread use of electricity. Despite centuries of technological progress and near ubiquitous use, batteries remain prone to the same inefficiencies and hazards as any device based on chemical reactions – sluggish reactions in the cold, the danger of explosion in the heat and the risk of toxic chemical leakages.

Another way of storing energy is to strain a material that then releases energy as it returns to its unstrained state. The strain could be linear like stretching and then launching a rubber band from your finger; or twisted, like a wind-up clock or toy. Over a decade ago, theoretical work done by researchers at the Massachusetts Institute of Technology suggested that strained chords made from carbon nanotubes could achieve impressive energy-storage densities, on account of the material’s unique  mechanical properties.

Diamond nanothreads could beat batteries for energy storage, theoretical study suggests
Anna Demmings, Physics World

Interphase...

Intro to Nano Energy: Lecture 5

Topics: Battery, Materials Science, Nanotechnology

What happens in a lithium-ion battery when it first starts running? A complex series of events, it turns out – from electrolytic ion reorganization to a riot of chemical reactions. To explore this early part of a battery’s life, researchers in the US have monitored a battery’s chemical evolution at the electrode surface. Their work could lead to improved battery design by targeting the early stages of device operation.

The solid-electrolyte interphase is the solid gunk that materializes around the anode. Borne from the decomposition of the electrolyte, it is crucial for preventing further electrolyte degradation by blocking electrons while allowing lithium ions to pass through to complete the electrical circuit.

The solid-electrolyte interphase does not appear immediately. When a lithium ion battery first charges up, the anode repels anions and attracts positive lithium ions, separating oppositely charged ions into two distinct layers. This electric double layer dictates the eventual composition and structure of the solid-electrolyte interphase.

Emergence of crucial interphase in lithium-ion batteries is observed by researchers
Shi En Kim, Physics World

Protocells...

This scanning electron microscope image was taken of artificial “protocells” created at Argonne’s Center for Nanoscale Materials, which have the ability to convert light to chemical energy through the use of a light-harvesting membrane. (Image by Argonne National Laboratory.)

Topics: Alternative Energy, Battery, Biology, Green Tech, Nanotechnology

By replicating biological machinery with non-biological components, scientists have found ways to create artificial cells that accomplish a key biological function of converting light into chemical energy.

In a study from the U.S. Department of Energy’s (DOE) Argonne National Laboratory, scientists created cell-like hollow capsule structures through the spontaneous self-assembly of hybrid gold-silver nanorods held together by weak interactions. By wrapping these capsules’ walls with a light-sensitive membrane protein called bacteriorhodopsin, the researchers were able to unidirectionally channel protons from the interior of the artificial cells to the external environment.

“Nature uses compartmentalization to accomplish biological functions because it brings in close vicinity the ingredients needed for chemical reactions,” said Argonne nanoscientist Elena Rozhkova, a corresponding author of the study. ​“Our goal was to replicate nature, yet use inanimate materials to probe how cells accomplish their biological tasks.”

Scientists harvest energy from light using bio-inspired artificial cells
Jared, Sagoff, Argonne National Laboratory

Lithium Magic...

Drive for innovation: Electric vehicles are a major target for R&D on novel battery materials. (Image courtesy: imec)

Topics: Battery, Chemical Physics, Green Tech

The batteries we depend on for our mobile phones and computers are based on a technology that is more than a quarter-century old. Rechargeable lithium-ion (Li-ion) batteries were first introduced in 1991, and their appearance heralded a revolution in consumer electronics. From then on, we could pack enough energy in a small volume to start engineering a whole panoply of portable electronic devices – devices that have given us much more flexibility and comfort in our lives and jobs.

In recent years, Li-ion batteries have also become a staple solution in efforts to solve the interlinked conundrums of climate change and renewable energy. Increasingly, they are being used to power electric vehicles and as the principal components of home-based devices that store energy generated from renewable sources, helping to balance an increasingly diverse and smart electrical grid. The technology has improved too: over the past two and a half decades, battery experts have succeeded in making Li-ion batteries 5–10% more efficient each year, just by further optimizing the existing architecture.

Ultimately, though, getting from where we are now to a truly carbon-free economy will require better-performing batteries than today’s (or even tomorrow’s) Li-ion technology can deliver. In electric vehicles, for example, a key consideration is for batteries to be as small and lightweight as possible. Achieving that goal calls for energy densities that are much higher than the 300 Wh/kg and 800 Wh/L which are seen as the practical limits for today’s Li-ion technology. Another issue holding back the adoption of electric vehicles is cost, which is currently still around 300–200 $/kWh, although that is widely projected to go below 100 $/kWh by 2025 or even earlier. The time required to recharge a battery pack – still in the range of a few hours – will also have to come down, and as batteries move into economically critical applications such as grid storage and grid balancing, very long lifetimes (a decade or more) will become a key consideration too.

There is still some room left to improve existing Li-ion technology, but not enough to meet future requirements. Instead, the process of battery innovation needs a step change: materials-science breakthroughs, new electrode chemistries and architectures that have much higher energy densities, new electrolytes that can deliver the necessary high conductivity – all in a battery that remains safe and is long-lasting as well as economical and sustainable to produce.

Beyond the lithium-ion battery, Jan Provoost, imec/Physics World