Can the waste heat from chips be used to charge a mobile phone? Will this good thing come true?

Many years ago, we at San Yi Life saw a statement on a social platform claiming that a certain mobile phone manufacturer had developed a technology that "generates electricity based on chip waste heat."

According to the relevant descriptions at the time, this technology claims to use a special power generation chip attached to the SoC, which can directly "absorb" the heat of the SoC and convert it into electrical energy. This can not only supplement the power of the mobile phone, but also indirectly help to cool the chip.

In our memory, such publicity attracted some attention at the time, but it quickly faded away, and there were no subsequent products related to it that were mass-produced and put on the market.

The related technology does exist, but mass production is almost impossible.

In fact, the method of "absorbing" waste heat from the chip and converting it into electrical energy does exist.

Simply put, it utilizes the characteristic of certain special materials that undergo a change in physical properties during the process of heating and cooling, causing them to deform due to heat absorption, then detach from the heat source, and return to their original shape when cooled. Through this repetitive process, this movement can be applied to the classic generator structure, thereby generating electrical energy. In fact, this is the basic principle of the well-known thermoelectric generator.

Of course, heat pumps also have a very obvious drawback, which is that if you want to cram it into a device as small as a mobile phone, it will involve the miniaturization of the mechanical structure of the generator (as well as the thermal expansion components), and this is basically unsolvable with current material technology. So this is also the fundamental reason why the "heat-absorbing power generation design" mentioned at the beginning of this article is difficult to be truly mass-produced.

Without the need for a mechanical structure, thermoelectrochemical cells bring new hope

However, with the advancement of technology, it seems that new solutions have emerged. According to a recent research result released by the University of Utah, the research team has invented a brand-new heat-absorbing power generation device based on "thermoelectrochemical cells".

According to the relevant information, the thermoelectrochemical battery does not have any mechanical structure inside. It purely relies on compounds to achieve the conversion of thermal energy to electrical potential energy. Therefore, it can be made very thin. It is claimed that the current version of the thermoelectrochemical battery, with an area of about 1 square centimeter, can generate approximately 0.001 watt-hour of electricity after each temperature cycle. Simply put, theoretically, it only needs 1000 such heat-absorbing cycles to produce 0.1 kilowatt-hour of energy. According to the common battery specifications of current smartphones, this is already enough to charge mainstream models to about 50% of their capacity.

Doesn't it sound very tempting? However, since the relevant team has not yet disclosed more data, the outside world does not know how much temperature difference is needed for the so-called "once heat absorption cycle," and how long the reaction time is needed to complete. At the same time, the cost of related thermochemical materials is still basically unknown (because if it is really cheap, it is hard to imagine that the relevant reports will not emphasize its cheapness).

Of course, compared to the basically theoretical and almost impossible to manufacture ultra-small heat pumps, thermochemical electrochemical cell technology does open up a possibility for the waste heat utilization of small mobile device chips.

In theory, it can replace button batteries, but cost may be the biggest problem.

For this reason, some believe that this new technology may help eliminate the currently heavily polluting button batteries. Of course, in principle, devices powered by button batteries already have low energy consumption. If thermochemical electrochemical cells are used to absorb environmental heat to power them, it is indeed a very environmentally friendly measure.

However, considering button batteries, as well as the devices powered by button batteries (usually various small sensors and timing devices) are mostly very cheap, so we at San Yi Life don't really think that thermoelectrochemical batteries will necessarily "benefit" them so quickly.

On the other hand, professional sports watches and wearable sensors with relatively high product premiums, but not high power consumption, seem to have a better chance of being the first products to benefit from thermoelectrochemical batteries. After all, a closer look at this market reveals that many of them are already using high-cost energy conversion devices such as solar cells. If thermoelectrochemical batteries are added, they may also be able to withstand it, and may even be more welcomed by specific user groups.

As for when it will become popular on smartphones, tablets, or more types of consumer electronics, it depends on the user demand at that time.