XNRGI Battery

[Rick C]

This company seems to have a battery that will provide energy for cars and other applications with a much higher density and lighter weight than Li-ion batteries. They talk about making "pores" in Si wafers with lithium anode material. Some of what they say is a bit odd. Since the anode is lithium, clearly the lithium is removed and redeposited during use. Yet they claim "No Li plating". They talk about using low cost Si wafers on older equipment, but show 12 inch wafers.

They claim to be lower cost than Li-ion, but not by a lot, $150 vs. $180/kWh. It is not hard to find articles that expect Li-ion prices to fall below $100/kWh by 2024 which is when XNRGI expects to be in cars at high volume.

Even if they are the same price as Li-ion batteries, if they can reduce the weight and size that would be a huge benefit. They also claim to have longer lifespan.

It will be interesting to see how they do.

--

Rick C.

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[Bill Sloman]

On Monday, July 22, 2019 at 10:45:06 AM UTC+10, Rick C wrote:
> This company seems to have a battery that will provide energy for cars and other applications with a much higher density and lighter weight than Li-ion batteries. They talk about making "pores" in Si wafers with lithium anode material. Some of what they say is a bit odd. Since the anode is lithium, clearly the lithium is removed and redeposited during use. Yet they claim "No Li plating".

They might mean that the lithium atoms only get electroplated onto silicon, rather than onto lithium atom stuck to silicon.

They'd need a lot of pores in the silicon to get enough surface area to be able to work with only a single, incomplete layer of lithium atoms, but that single atom-thick layer will have distinctly different thermodynamic properties than a layer of lithium on lithium.

Perhaps they only mean that the lithium won't block the pores by plating up thick enough deep in the pores to limit access to the electrolyte, but how you'd manage that isn't obvious.

> They talk about using low cost Si wafers on older equipment, but show 12 inch wafers.

So what? Presumably they are talking about pits in the silicon surface rather than pores running through it, where the maximum depth of the pit is limited by its diameter, so larger pits, deeper pits produced by an older fab working to coarser design rules would give them the same surface area.

IIRR laser-drilled pits can go a lot deeper for the same diameter as etched pits - aspect ratios approaching 100:1 versus 10 or 15:1 - but they'd have to be drilled one pit at time, and you'd get amorphous silicon condensed onto the single crystal wafer surface.

They claim to be lower cost than Li-ion, but not by a lot, $150 vs. $180/kWh. It is not hard to find articles that expect Li-ion prices to fall below $100/kWh by 2024 which is when XNRGI expects to be in cars at high volume.

Even if they are the same price as Li-ion batteries, if they can reduce the weight and size that would be a huge benefit. They also claim to have longer lifespan.

It will be interesting to see how they do.

Absolutely. Nano-engineering the electrolytic surface has to be the way to go.

--
Bill Sloman, Sydney

 

[Rick C]

On Monday, July 22, 2019 at 2:31:47 AM UTC-4, Bill Sloman wrote:

On Monday, July 22, 2019 at 10:45:06 AM UTC+10, Rick C wrote:
This company seems to have a battery that will provide energy for cars and other applications with a much higher density and lighter weight than Li-ion batteries. They talk about making "pores" in Si wafers with lithium anode material. Some of what they say is a bit odd. Since the anode is lithium, clearly the lithium is removed and redeposited during use. Yet they claim "No Li plating".

They might mean that the lithium atoms only get electroplated onto silicon, rather than onto lithium atom stuck to silicon.

They'd need a lot of pores in the silicon to get enough surface area to be able to work with only a single, incomplete layer of lithium atoms, but that single atom-thick layer will have distinctly different thermodynamic properties than a layer of lithium on lithium.

Perhaps they only mean that the lithium won't block the pores by plating up thick enough deep in the pores to limit access to the electrolyte, but how you'd manage that isn't obvious.

They talk about using low cost Si wafers on older equipment, but show 12 inch wafers.

So what? Presumably they are talking about pits in the silicon surface rather than pores running through it, where the maximum depth of the pit is limited by its diameter, so larger pits, deeper pits produced by an older fab working to coarser design rules would give them the same surface area.

Their site is actually one of the worst I've ever seen, but there is a paper that has some technical detail, just not much. They show one illustration that looks like there are through holes in the Si wafer with anode on one end and cathode on the other. They also talk about coating the back of the wafer with non-conductive layer to solve some problem I forget.

I assumed any fab that is mostly depreciated won't use 12 inch wafers, but maybe they've been out longer than I recall. I do recall the industry cried "no mas" at the 12 inch point indicating they weren't sure 12 inches was better than 10 and definitely didn't want to go to 14 inches in the foreseeable future. I guess it's past the point of diminishing returns.


> IIRR laser-drilled pits can go a lot deeper for the same diameter as etched pits - aspect ratios approaching 100:1 versus 10 or 15:1 - but they'd have to be drilled one pit at time, and you'd get amorphous silicon condensed onto the single crystal wafer surface.

I haven't seen anything that indicates the Si is anything other than a support. So likely none of this matters. They do show very deep pores in the illustrations.

They claim to be lower cost than Li-ion, but not by a lot, $150 vs. $180/kWh. It is not hard to find articles that expect Li-ion prices to fall below $100/kWh by 2024 which is when XNRGI expects to be in cars at high volume.

Even if they are the same price as Li-ion batteries, if they can reduce the weight and size that would be a huge benefit. They also claim to have longer lifespan.

It will be interesting to see how they do.

Absolutely. Nano-engineering the electrolytic surface has to be the way to go.

--

Rick C.

+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209

 

[Bill Sloman]

On Tuesday, July 23, 2019 at 12:57:10 AM UTC+10, Rick C wrote:

On Monday, July 22, 2019 at 2:31:47 AM UTC-4, Bill Sloman wrote:
On Monday, July 22, 2019 at 10:45:06 AM UTC+10, Rick C wrote:

<snip>

So what? Presumably they are talking about pits in the silicon surface rather than pores running through it, where the maximum depth of the pit is limited by its diameter, so larger pits, deeper pits produced by an older fab working to coarser design rules would give them the same surface area.

Their site is actually one of the worst I've ever seen, but there is a paper that has some technical detail, just not much. They show one illustration that looks like there are through holes in the Si wafer with anode on one end and cathode on the other. They also talk about coating the back of the wafer with non-conductive layer to solve some problem I forget.

I assumed any fab that is mostly depreciated won't use 12 inch wafers, but maybe they've been out longer than I recall. I do recall the industry cried "no mas" at the 12 inch point indicating they weren't sure 12 inches was better than 10 and definitely didn't want to go to 14 inches in the foreseeable future. I guess it's past the point of diminishing returns.

There's no direct connection between the maximum size of wafer that a fab can handle and the design rules that they can meet, but wafer size has gone up over the years, and minimum feature sizes have gone down, so there's a correlation between the age of the fab, the size of wafer they can handle and the minimum feature size they can achieve.

The last time I knew much about it was around 1987, when the Cambridge Instruments EBMF 10.5 couldn't handle wafers more than five inches in diameter, and the machine I was working on then could have handled six inches wafers if it hadn't been cancelled.

--
Bill Sloman, Sydney