Enevate was showing SemiAccurate a new battery at CES, Silicon-Lithium-Ion. As with all new battery types it promises a fair number of advances, something which the underlying chemistry supports.
You are all probably familiar with rechargeable battery technology, especially the now standard Lithium-Ion or Li-Ion cells that a found in almost all modern electronics. These cells have changed very little since they were invented in the 1990s with the biggest advances coming from packaging and construction, not chemistry. There are a few promised advances on the horizon but none have made it to the mass market for one reason or other.
Yes they look like batteries
Enevate is doing something quite different with their cells, starting with using Silicon as the anode material. This allows them to effectively use the charge carrying chemicals as the anode material itself rather than copper or other metals, or at least for most of it. The result is something they call a silicon dominant composite. There still needs to be some old-fashioned anode materials but using the active ingredients for most of it is a massive step forward in density. If I have already lost you, what I basically just said was the ratio of active ingredients to physical structure went way up.
Then things get a little interesting. Instead of the normal charge and ion passing a battery does, the Si-Li-Ion batteries work by having the Silicon alloy with the Lithium itself. Enevate would not go into the details of the mechanism for obvious secret sauce protection reasons, but this explanation was enough to know they are onto something very different with their cells.
Details aside, what do they promise? Officially a 20-30% higher charge density on a volume or mass basis compared to current state of the art cells. That is a pretty large gain right there but since it has significantly lower impedance than more traditional batteries, this can translate into 50% higher run times. Basically it is quite a bit better than normal batteries no matter how you measure it, at least if Enevate’s claims pan out.
More interesting is something the company calls eBoost mode, effectively using the charge below the normal 3.3v cutoff point. Modern Li-Ion cells are known for not having much energy remaining in the cell once you go below 3.3v, they run until they die with a fairly constant voltage. This is a good thing and allows you to run a cell almost ‘dry’ before you have problems, quite the contrast to older NiCd type batteries. Most consider this a feature because, lifetime aside, almost 100% of the rated capacity is usable.
Enevate’s chemistry is quite different from Li-Ion cells as you probably understand by now, and the energy left in the cell once it hits 3.3v is quite large, about 25% of the above 3.3v rated capacity. Normally the device and/or firmware would prevent you from using this energy because the closer to zero you drain a cell, the more damage you do to it. This is why electric cars only run a battery from 20-80% capacity, moving outside of that range degrades the cell quite a bit faster than staying in the safe zone.
With eBoost you can run the cell down to about 2.7v to get that extra 25% battery life, but it will come at the effective cost of several recharge cycles. Enevate would not say how many exactly, but were quite direct in saying you didn’t want to do it often, emergencies only. No, contrary to what you might think, Facebook is NOT an emergency, especially while driving. Put the damn phone down, there is a world outside you 1.5 ton metal death missile hurtling at that tree, likes can wait.
Back to batteries the end result of the new Si-Li-Ion cells are a claimed 50% more runtime in the same package or weight as current state of the art cells. Enevate also claims a 90% charge in 15 minutes but we are not sure how feasible that is with current phone infrastructure. Qualcomm’s QuickCharge 3.0 should provide the wattage but most existing chargers would be hard pressed to supply that level in a sustained fashion. Toss in the eBoost feature and you have another 25% runtime, with a cost attached, but if you need it, you probably need it.
The whole concept of Enevate’s new cells is quite intriguing. If the end result holds up to their promises, the next generation of batteries could be a step change forward in capacity and charge times, not the normal incremental dribble. Production is said to be starting this year so we should know for sure in a few months. The status quo of what the phone makers taketh has not been matched by the chemistry side giveth-ing for too long, the sooner this changes the better for us all.S|A