Nissan is considered one of a number of automakers that see solid-state battery expertise as a possible game-changer for EVs going into the following decade. In-house, it plans to each good improvement of all-solid-state battery (ASSB) cells and set up easy methods to make them, with the tech as a consequence of make it right into a manufacturing EV by 2028.
If all goes effectively, Nissan needs to lean on the tech so extra car sorts—particularly SUVs, pickups, and vans—make sense in totally electrical type by the tip of the last decade.
That gave the impression to be the gist behind the Hyper Tourer idea Nissan displayed on the Tokyo auto present final week, suggesting a really skinny, flat solid-state battery pack under the ground, affording long-range cruising with out the packaging compromise.
Nissan Hyper Tourer idea
Nissan Hyper Tourer idea
Nissan Hyper Tourer idea
Versus the present lithium-ion cell tech in EVs, Nissan is aiming to successfully double the vitality density on the pack stage, whereas slicing the quick charging time by two-thirds.
On the similar time, lithium-ion chemistries and different battery sorts are evolving and enhancing. In a roundtable interview final week on the Tokyo auto present, Nissan’s world R&D chief Kazuhiro Doi informed Inexperienced Automotive Experiences that solid-state cell tech can’t simply be an incremental enchancment over lithium-ion.
To hit these objectives, Doi underscored, it is going to ideally must go together with no cooling in any respect.
Strong-state runs scorching and that’s OK
“Within the case of ASSB, perhaps we will remove the cooling,” he stated, emphasizing that it’s nonetheless not mounted on a ultimate design, however it’s aiming to keep away from it fully.
As Doi confirmed to some raised eyebrows and verified to Inexperienced Automotive Experiences, which means no water cooling, no forced-air cooling, and never even any passive cooling—definitely completely different than what some automakers have advised.
2011 Nissan Leaf – battery pack cutaway
It’s a little bit of a loaded topic. Nissan underestimated the cooling wants of the unique battery cells used within the Nissan Leaf, which degraded rapidly in scorching climates when parked over scorching blacktop or fast-charged too regularly. A subsequent battery-chemistry change in 2015 helped clear up that, and since then Leaf battery degradation has been significantly better.
Eliminating the cumbersome water-cooling system in different trendy EVs has been a objective for improvement engineers. Mercedes thought-about air-cooling in its latest EQXX idea, presaging its new technology of EVs—nonetheless with lithium-ion cells—and finally determined towards it.
However Nissan has extra hands-on expertise with the tech already, and the rationale behind going with out cooling for ASSB is easy: It’s OK for them to get a lot hotter than what can be thought-about regular for different EV batteries, and the cells have a large temperature candy spot—from room temperature all the way in which as much as 100 levels C or 212 levels F.
To keep up the benefit over lithium-ion chemistries and make all the event worthwhile, Nissan might want to have a superior product by then that wouldn’t be depending on cooling, Doi once more emphasised.
For many lithium-ion cells, the temperature threshold is about 60 C or 140 F, and quick charging instances are restricted to stop cell temperatures from approaching that temperature. With out worrying a lot about temperature, Nissan’s solid-state cells would possibly have the ability to cost to close 100% in about quarter-hour.
Nissan Surf-Out, Max-Out and Cling-Out ideas
Nissan sees solid-state going large first
Strong state may very well be relevant to all sorts of automobiles. Whereas some corporations—Toyota, as an illustration—have hinted that solid-state cells would possibly first seem in hybrids. Nissan believes one kind of mannequin makes extra sense to take solid-state first: large, long-range, totally electrical automobiles.
Doi defined that vehicles, vans, and SUVs require far more vitality, “but when we make the most of that right this moment with lithium-ion battery tech, the scale is large.” Chopping the cooling system out of the equation would imply smaller packaging and far much less complexity for the battery pack, permitting it to unencumber area for roomier automobiles—or, doubtlessly, for extra vary and fewer mass.
2022 GMC Hummer EV
Juggling energy, security, cycle life
This time round, Nissan must get the battery composition proper from the beginning, and there are longevity hurdles but to unravel. In a laboratory scenario with scaled-up check cells it’s seeing round 200 cycles—not anyplace close to sufficient for a manufacturing EV but.
After first working with single-layer cells simply 2 cm throughout within the laboratory, Nissan nonetheless plans to ascertain a pilot line for cells about 10 cm throughout in 2024. The precise manufacturing cell might be “a lot bigger” than that, Doi stated. Nissan plans to make larger-format cells on the pilot facility, as it really works out the scale of the plant it would must ramp up manufacturing.
As Doi had beforehand stated, Nissan is incorporating its personal nail-piercing assessments and X-ray imaging into its research of the solid-state cells, which might be subjected to rigorous security and sturdiness testing. The Nissan Leaf has had no cases of fires or thermal runaway, and it’s constructing these new cells with the identical security priorities.
Nissan solid-state battery prototype manufacturing
Nissan’s solid-state tech advantages from a partnership with NASA and UC San Diego by which AI strategies helped select the most effective interlayer to stop the expansion of lithium dendrites that may ultimately piece by, short-circuiting the cells. The high-ion-conductive electrolyte was chosen for stability, with the anode for high-power potential.
Nevertheless it’s not achieved fine-tuning the cells and isn’t in a position to give specs for them fairly but. Cell efficiency is just not solely mounted by chemistry however by the cathode and anode layers, Doi defined. A thicker cathode will yield extra vitality density but in addition get in the way in which of cost charges. “First we have to repair the chemistry, and as soon as we repair the chemistry we will estimate the efficiency per cell,” he stated.
Nissan ASSB vs lithium-ion
Strong-state tech evolution
Doi additionally emphasised that there might be loads of evolution of the chemistry. The addition of nickel for vitality density and vary in lithium-ion cells is one instance, he stated, and the identical kind of factor will occur for stable state.
ASSB apart, high-manganese and sulfur-based chemistries are the following finest hope, Doi says. “Then we will make the most of that even for the small vehicles—I feel the potential could be very engaging,” he stated.
Nissan is concentrating on a value of simply $75 per kwh for solid-state cells, which could put it on par with lithium-ion on the finish of the last decade. If it may possibly use ASSB for larger automobiles, the candy spot for smaller EVs is likely to be in some mixture of these chemistries with stable state—a good lower-cost, less-resource-intensive answer with out the life-cycle challenges. Cooling for such a mix is but to be decided, although.