Physics Colloquium

In 1815 Michael Faraday visited Alessandro Volta in Italy and was presented with a voltaic pile – the first (non-biological) device to convert chemical energy into an electrical current. Armed with a controllable source of electricity, Faraday embarked on a series of experiments that led to the electrical dynamo and the electrical motor. His practical inventions were seized upon by Maxwell to construct the theory of electromagnetism, which itself has been the foundation of much of modern physics and technology. By 1900 the world had electrically powered vehicles, and within a few decades many countries had built a substantial electrical grid. In 1911 Kamerlingh Onnes discovered superconductivity, the perfect electrical wire, which makes in principle the most efficient magnets for motors and conductors for electrical transport. So combustion engines should be toast.

However, the availability of cheap fossil fuels and the challenges of building low-cost electrical storage systems gave heat engines a century of dominance that is only now coming to an end. We now must unwind that century-long hiatus and build an electrified economy based on renewable power.

The impact of some low-carbon energy technologies, such as solar, wind, and electrical storage, is now exponentiating. The world's first terawatt of modern renewable capacity was completed in 2018, and the second terawatt about 5 years later, at a cost of about 1$ per Watt. (The world's consumption of power of all kinds is about 20 terawatts on average.) While nuclear is largely stagnant it remains important and could revivify, and there is considerable interest in the possibility of compact fusion reactors. But scaling is not easy because the science is not yet done.

In this talk I will use batteries and wires as examples of the research ecosystem because they have many parallels across renewable technologies. Despite its venerable history, electrochemical technology is still immature. Electrochemistry must manipulate materials and chemical reactions on the nanoscale, yet its products are manufactured by the ton. The fundamental components of a battery – anode, cathode, electrolyte, control system – can be chosen from a vast palette of chemistries, but the complicated interplay that makes a functioning device will emerge only after the pieces are joined together at a point very distant from the fundamental invention.

Superconducting wires – especially with high temperature superconductors (HTS) - enable higher current densities and higher magnetic fields, without which we will likely not have compact fusion devices, next-generation MRI, ubiquitous nuclear magnetic resonance, or a muon collider (see NAS report). The materials in batteries and HTS wires are strongly-correlated metals whose underlying science is poorly understood despite that we need to manufacture them at scale.

Join via Zoom:
https://caltech.zoom.us/j/89860951893
Meeting ID: 89860951893

The colloquium is held in Feynman Lecture Hall, 201 E. Bridge.