What are silicon-carbon batteries used in new phones and how are they different from conventional lithium-ion batteries?

How different are silicon-carbon batteries from lithium-ion ones?

Silicon carbon batteries aren’t that different from lithium-ion batteries. In fact, in both technologies, the cathode is made out of lithium, while on the new silicon-carbon batteries, instead of using conventional graphite as the anode, a silicon-carbon composite is used, which has a higher energy storage capacity.

It is estimated that a lithium battery with a graphite anode will have an energy storage capacity of up to 372 mAh/g, while a silicon-carbon battery can hold up to 470 mAh/g, which makes silicon-carbon much more energy-dense compared to graphite. However, these are theoretical values, and in real life, the energy density will vary from device to device.

A silicon-carbon battery with the exact same dimensions as a lithium-ion battery will be able to hold more charge.

However, silicon-carbon batteries also have some of their own issues, such as silicon swelling, which could drastically reduce battery capacity and degrade the cell much more quickly compared to a lithium-ion battery. This means a silicon-carbon battery will be smaller in size when discharged and will swell after charging, while the volume of the battery remains the same in the case of a lithium-ion battery.

Upcoming phones like the Oppo Find X8 Pro, Vivo X200 Pro, iQOO 13, OnePlus 13, and Realme GT 7 Pro are expected to be the first set of flagship Android smartphones to come equipped with silicon-carbon batteries. As per reports, these smartphones pack massive batteries, averaging around 6,000 mAh capacity, which are much bigger than their predecessors, while the phones themselves have gotten slimmer.