a bonobo humanity?

And now for something completely different.

An article in a recent issue of The Economist (August 26- September 1 2023) , which I read mainly for the political and technological stuff, as economics is largely gibberish to me, deals with the development of solid state Li-ion batteries for EVs, and their scaling up for a new generation of such vehicles. So this piece is for educating myself, or trying to, on solid state electrolysis and how such batteries will, maybe, hasten the end of the infernal combustion engine for families and hoons everywhere.

As the article points out, there are three main issues which might be preventing the greater uptake of EVs – range, cost and charging times. All of which can be fixed with better-performing and cheaper batteries. Easy-peasy.

Current or ‘traditional’ lithium-ion batteries took quite a while to go from the drawing-board to useful application:

Although they were invented in the late 1970s, Li-ion batteries… were not fully commercialised until the early 1990s, at first for portable electronic devices, such as laptop computers and cell phones, and then as bigger versions that could be used to power a new generation of EVs.

The solid state version of these batteries, which are potentially safer, longer lasting and more efficient, have been promised for some time, but they’re now on the point of commercial reality, or just about. But what does ‘solid state’ mean, and why aren’t current Li-ion batteries solid – and what makes them liquid?

It’s all about the electrolyte, the key component of all batteries:

… electrolytes are used in a liquid form for good reason. Ions are charged particles, and are created at one of the batteries electrodes, the cathode, when the cell is charged, causing electrons to be stripped from lithium atoms. The electrolyte provides a medium through which the ions migrate to a second electrode, the anode. As they do so, the ions pass through a porous separator that keeps the electrodes apart to prevent a short-circuit. The electrons created at the cathode, meanwhile, travel towards the anode along the wires of the external charging circuit. Ions and electrons reunite at the anode where they are stored. When the battery discharges, the process reverses, with electrons in the circuit powering a device – which in the case of an EV is its electric motor.

This explanation, from the article referenced below, requires some explaining, at least for me. So, from the beginning, electro-lysis (coined by Faraday) means cutting, or splitting, by means of electricity. Stripping electrons (negatively charged) from atoms, thus ionising them (positive charge). The level of electric pressure, or voltage, required for electrolysis to occur is called the decomposition potential. 

So the question I ask myself, in my non-scientific way, is – can electrolysis be applied to any element? Presumably, with a Li-ion battery, it’s applied to lithium, which is an ‘alkali metal’. Interestingly, according to Wikipedia,

Australia has one of the biggest lithium reserves and is the biggest producer of lithium by weight, with most of its production coming from mines in Western Australia.

So, a quick look-up tells me that electrolysis can be and is applied to many elements and compounds and substances, including water (for the production of hydrogen fuel, though that’s a potentially fraught process). Anyway, it seems that, though the electrolyte in a Li-ion battery is liquid ‘for good reason’, I still don’t know what that reason is, though I’m guessing that it’s because the ions can move more readily through liquid to the terminals (cathode and anode). So, ‘the most common electrolyte in lithium batteries is a lithium salt solution such as lithium hexafluorophosphate (LiPF6)’. Polymer gels are also used, but the development of a solid state battery has been a kind of holy grail for some time, as this would, or should, reduce flammability and increase voltage, cycling performance, strength and overall lifespan. One of the major hurdles is cost, as companies seek to develop a particular type to scale up. Over the past ten years or so, as it has become clear that EVs will be the future of motoring, the race has been on to produce effective and economic solid state batteries (SSBs). Here’s how Wikipedia puts it:

In 2013, researchers at the University of Colorado Boulder announced the development of a solid-state lithium battery, with a solid composite cathode based on an iron–sulfur chemistry, that promised higher energy capacity compared to already-existing SSBs. In 2017, John Goodenough, the co-inventor of Li-ion batteries, unveiled a solid-state glass battery, using a glass electrolyte and an alkali-metal anode consisting of lithium, sodium or potassium. Later that year, Toyota announced the deepening of its decades-long partnership with Panasonic, including a collaboration on solid-state batteries.

Various solids are being trialled, including ceramics and solid polymers. The US company QuantumScape has teamed with Volkswagen to mass-produce lithium metal batteries, which use metallic lithium as an anode. My mind is glazing over as I try to understand the technology involved, but here’a a quote from QuantumScape’s website:

QuantumScape’s technology platform is designed to pair with a variety of cathode chemistries — with the potential to significantly improve the energy densities of today’s Nickel Manganese Cobalt (NMC) and Lithium Iron Phosphate (LFP)-based battery cells. This capability enables optimization for diverse energy storage applications and gives our platform the flexibility to benefit from future cathode chemistry advancements.

They’re hoping for commercial availablity of their product by the end of next year, apparently. The same webpage tries to answer a number of FAQs, such as the benefits of solid state lithium, re weight and volume, the effects on EV range, the nature of the separator material, and co-existence with other current and emerging technologies.

I think that’ll do for my amateur analysis, for now, but I do hope to keep an eye on this technology, and the rise of EVs and surrounding infrastructure going forward.

References

‘The race to build a superbattery’,  The Economist, August 26 – September 1 2023

https://en.wikipedia.org/wiki/Electrolysis

https://en.wikipedia.org/wiki/Lithium_mining_in_Australia

What Is Battery Electrolyte and How Does It Work?

https://en.wikipedia.org/wiki/Solid-state_battery

https://www.quantumscape.com/technology/