0:07 to really understand where we are as a
0:08 company and where we're headed in terms
0:11 of the technology let's take a step back
0:12 and talk about the fundamentals of
0:15 lithium-ion batteries
0:17 a lithium-ion battery is an
0:19 electrochemical cell that consists of a
0:21 cathode and an anode
0:24 the cathode is a piece of aluminum foil
0:25 with some type of lithium compound on
0:26 top of it
0:29 in our case this lithium compound is
0:33 lithium iron phosphate or lifepo4
0:35 the anode which is the negative side of
0:37 the battery is comprised of a piece of
0:40 copper foil with graphite coated on it
0:42 graphite is c6
0:44 in between there's a thin plastic
0:46 separator typically polyethylene
0:49 polypropylene and this entire structure
0:51 is filled in with a liquid
0:53 this liquid electrolyte has a lot of
0:57 lithium ions inside of it li plus
0:59 now when you charge this for the very
1:01 first time you're basically pumping
1:04 electrons from the cathode to the anode
1:06 and when the electron comes off of the
1:08 cathode the lithium iron phosphate
1:11 becomes a lithium ion plus the electron
1:14 that gets pumped out plus iron phosphate
1:15 and that's what's left behind on the cathode
1:17 cathode
1:19 the lithium ion that came out basically
1:21 migrates through the electrolyte towards
1:24 the anode or the graphite on the
1:26 negative side and recombines with the
1:28 electron that's been pumped through the
1:30 charger and now the lithium ion plus the
1:33 electron reacts with the graphite to
1:36 form a lithiated graphite
1:38 and when this cycle is complete
1:41 then the battery is fully charged
1:43 as the battery discharges the reverse
1:45 reaction happens
1:52 a lead acid battery is also an
1:54 electrochemical cell
1:57 in its discharged state both the anode
1:59 and the cathode are composed of lead
2:02 sulfate and the electrolyte is sulfuric
2:05 acid and within the electrolyte protons
2:07 or hydrogen ions are allowed to move
2:10 back and forth between the electrodes
2:12 as the battery is charged
2:14 we're pumping once again electrons from
2:18 one side to the other and on the cathode
2:20 what's formed is lead oxide and on the
2:23 anode pure lead metal is formed and the
2:25 electrolyte becomes very rich in
2:27 sulfuric acid
2:28 so you can see that in a lead acid
2:31 battery there's quite a bit of both lead
2:34 and sulfuric acid that are required in
2:35 order for this electrochemical cell to function
2:37 function
2:40 well lead is highly toxic and sulfuric
2:42 acid is highly corrosive
2:44 there's a couple of fundamental
2:46 differences between how a lithium ion
2:48 battery works and how a lead acid
2:50 battery works even though they're both
2:52 electrochemical cells
2:54 for example in a lead acid battery the
2:57 electrolyte is sulfuric acid which
2:59 actually is water with sulfate and
3:01 hydrogen ions dissolved in it
3:03 one thing to note is if you have a high
3:05 charge on water you can cause
3:08 electrolysis of water which can react to
3:10 form hydrogen and oxygen of course
3:12 that's an explosive mixture and that's
3:14 why it's important that lead acid
3:17 batteries are vented in the lithium ion
3:19 case we have an organic electrolyte we
3:21 actually don't require venting and the
3:24 cells are all individually completely
3:26 sealed and that's why we're able to
3:28 mount lithium-ion battery packs in
3:30 unvented compartments
3:32 another fundamental difference is just
3:33 the weight
3:35 obviously in a lead acid battery there's
3:37 a lot of lead lead is a very heavy
3:39 element and in a lithium ion battery the
3:42 lithium itself is extremely light but
3:44 the other components the graphite and
3:46 the iron phosphate in a lithium iron
3:49 phosphate battery by comparison in terms
3:51 of energy they deliver are much lighter
3:55 than the lead acid electrochemical cell
3:57 a third thing that can happen in a lead
3:59 acid cell is you get what's called sulfation
4:00 sulfation
4:02 where you get sulfate crystals forming
4:05 on the electrodes of a lead acid battery
4:07 and that significantly increases the
4:09 impedance of the battery which makes it
4:11 difficult to even get any power out of
4:13 it in that situation
4:14 it's also a very difficult situation to
4:18 resolve if even at all possible and that
4:20 sort of sulfation phenomenon does not
4:23 exist in a lithium-ion battery
4:24 so because of these fundamental
4:26 differences between our lithium-ion
4:29 batteries and lead acid batteries our
4:32 batteries are safer longer lasting
4:34 lighter more reliable
4:36 and that's why we say for deep cycle
