One new smartphone trend coming in 2025 is larger batteries. According to industry sources on the 25th, Chinese smartphone manufacturers Oppo, OnePlus, Xiaomi's Redmi, and Realme are developing smartphones with batteries over 6000mAh (milliampere). This figure exceeds the battery capacity of the iPhone 16 Pro Max at 4,685mAh.  

Oppo is expected to release a smartphone with a 7000mAh battery capacity in 2025. It will support the company's self-developed 80W SuperVOOC ultra-fast charging. The focus is on increasing the actual smartphone usage time. However, the company is avoiding revealing specific details.

Mid- to low-priced brand OnePlus will release the Ace 5 and Ace 5 Pro models with a 6000mAh battery capacity on the 26th of this month. The Ace 5 has a 6,285mAh battery capacity and supports 80W wired charging, while the higher-end model, the Ace 5 Pro, has a 6,100mAh battery and supports 100W wired charging.

Realme is preparing a smartphone with an 8,000mAh battery. It will be the largest smartphone battery capacity in the world. “Realme is conducting next-generation battery capacity experiments for its next-generation flagship smartphone, the ‘Realme GT8 Pro.’”

Realme is testing the safety and performance of a 7,000mAh battery that supports 120W fast charging, a 7,500mAh battery that supports 100W fast charging, and an 8,000mAh battery that supports 80W fast charging. It is said that the 7,000mAh battery that supports 120W fast charging takes about 40 minutes to fully charge.

The batteries that Chinese manufacturers are developing are the same size as existing batteries, but they have increased the capacity by using the new material high silicon. High silicon has a larger capacity per unit weight than the cathode material of existing lithium-ion batteries, which can maximize the battery charging speed and capacity. However, commercialization has been difficult due to safety issues. However, commercialization is on the way as Chinese battery manufacturer CARL has recently succeeded in strengthening durability.

There's a good report on the new batteries coming to Android phones in 2025 by Notebook Check and Android Authority.

A rumor from ETNews surfaced in 2023 stating that Apple would be tentatively introducing new battery technology for 2026 The report noted that "iPhones. Apple is directly participating in the development of battery materials such as positive and negative electrode materials, and is aiming to develop a completely new battery with significantly improved performance compared to existing ones.

Apple is known to be pursuing a completely new composition that is different from the existing one in order to improve performance by mixing raw materials such as nickel, cobalt, manganese, and aluminum to make cathode materials. They are also reviewing carbon nanotubes (CNTs) as a conductive material to improve battery material performance. A conductive material is a material that promotes the movement of electrons between the cathode active material and the anode active material. CNTs, which have recently been attracting attention as a secondary battery conductive material, can show excellent performance even with a smaller amount than the existing conductive material.

The development of cathode materials is progressing toward dramatically increasing the silicon content. Graphite is currently used as a secondary battery cathode material, but using silicon instead of graphite can increase battery capacity and shorten the charging and discharging time. However, silicon has a problem with its volume expanding during the charging and discharging process. Apple is interpreted to have secured technology to overcome the expansion problem by using silicon.