MWC is currently being held in Barcelona, Spain, and Xiaomi is one of the many exhibitors at the trade show. On February 28, founder Lei Jun released a pre-recorded video of a 4100mAh battery being charged in only 5 minutes using a new 300W wired charger. The video shows that Redmi Note 12 Pro+ reached 20 percent in just a little over one minute, followed by the 50 percent mark in 2 minutes 12 seconds, and then 100 percent in just a little under 5 minutes.
The company said the battery here packs a customized 6:2 charge pump chip, and the conversion efficiency of the chip is as high as 98%. Compared with the conventional 4:2 charge pump scheme, it solves the problem of heating in the charging path.
Multiple charge pumps allow for a decentralized layout, which effectively avoids heating and prolongs high-power charging time. The power meter indicated a peak input of a little over 290W for the charger while managing to sustain a 280W and above charging output for around two minutes.
Conventional graphite cathode charging methods have difficulty providing faster reaction speeds, which is the biggest bottleneck in battery charging speeds. Xiaomi is now introducing new carbon materials into mobile phone batteries which, compared with graphite, the hard carbon structure is looser and more disordered, which can provide a looser reaction path for lithium ions. The cathode made by mixing carbon and graphite in a specific proportion can greatly improve the charging speed and ensure a higher energy density.
In addition, the electrodes’ thickness has been greatly reduced by 35%. Together with an improved electrolyte formula, this lithium ion battery can pack a higher power density with a faster charge and discharge rate, while apparently reducing the amount of heat produced in the process.
Structurally, these ultra-thin cells are then stacked with thermal materials in between as part of a new “sandwich” design, in order to optimize heat dissipation while making better use of internal space. With a 43% increase in power, its volume is exactly the same as that of Xiaomi‘s previous 210W charger.