Daily Authority: ???? High-silicon batteries?

In short:

• Battery technology is more crucial than ever for us, our smartphones, and at a much bigger scale, for electric vehicles.
• The focus is usually on the anode material: while cathode materials have been perfected, increasing the energy density of the formerly graphite anode is the name of the game, without adding considerable expense for rare materials, or safety problems.

But also:

• Xiaomi has announced that its new technology is “High-Silicon Lithium battery technology,” which offers more capacity at the same volume, increasing its battery capacity in phones by up to 10%, starting from mid-2022.
• (It’s on the right, in the image above) 
• How? The high-silicon aspect, Xiaomi says, means “a claimed three-fold increase in the battery’s silicon content.” 
• There’s also mention of a very abstract “fuel-gauge chip” that “helps battery longevity and safety,” somehow. (If there’s a chip that helps battery longevity and safety, why wouldn’t that be in a battery made right now?)

What is high-silicon exactly?

• So, why has no one else offered high-silicon batteries? Why doesn’t Xiaomi have 5x or 10x the amount of silicon?
• I’m not sure exactly, and I welcome readers to write in on this. A look at papers about battery technology suggests that silicon is a “promising anode material for lithium-ion and post-lithium-ion batteries,” but suffers from “a large volume change upon lithiation and delithiation,” or to say it in plain English: it suffers a “huge volume change during the electrochemical process.”
• Therefore, adding too much silicon would require a bundle of tricks to increase volume without safety risks from battery expansion. 
• Other papers suggest adding composites and alloys to match benefits without volume problems.
• So, I don’t know, Xiaomi’s detail here is light and fluffy, but there’s a chance we’ll find out more in time.

???? The OnePlus Nord 2 CE specs may have just leaked: Mediatek Dimensity 900 chipset and faster wired charging (Android Authority).

???? Holiday reading: 19 book recommendations from the Ars staff. Huh, I’ve only read two of these, including The Spy Who Came in from the Cold by John Le Carré (Ars Technica).

Tristan Rayner, Senior Editor