While everything from bankruptcies to lack of capacity utilization seems to characterize the state of companies producing batteries for electric vehicles (EVs), here’s Jeff Deaton walking through a 475,000-sq. ft. plant in Smyrna, TN, a stone’s throw away from the 5.9-million-sq. ft. plant where Nissan produces the Altima, Maxima, Pathfinder, Infiniti JX35, and . . . the Nissan LEAF. An electric vehicle. Deaton is the plant manager of the Nissan Battery Plant, the largest lithium-ion battery (Li-ion) plant in the United States, one of three plants that Nissan has established (the other two are in England and Japan), a plant that is capable of producing up to 200,000 batteries per year. And they are building batteries in Smyrna.
Given that sales of the LEAF (which, incidentally, is produced on the same production line at the assembly plant with the Altima and Maxima, a testament to Nissan’s manufacturing flexibility) are nowhere near the 200,000 per year mark (in 2012, 9,819 LEAFs were sold in the U.S.), the company is confident in the technology, which explains the construction of the battery plant in Tennessee. What’s more, Nissan has an objective to localize production whereby it will have the ability to manufacture 85% of its U.S. sales volume in North America by 2015.
Echoing that objective: “Build where you sell,” says Mark Swenson, Nissan vice president, Production Engineering and Component Facilities, who heads up both vehicle and powertrain production for Nissan in the U.S., Mexico, and Brazil. He adds that another reason why they’ve built the battery plant is because, “We want to have this as a core competency.” While other OEMs outsource their battery build, Nissan is taking an alternative approach.
In addition to knowledge, Swenson says that localization provides other advantages. “The logistics benefits are huge,” he says. He adds that it also provides protection against currency fluctuations.
The battery was developed by Automotive Energy Supply Corp., a joint venture between Nissan and NEC.
According to Swenson, the LEAF build at the vehicle assembly plant is fairly similar to building the cars with internal combustion engines, with the engine decking being replaced by the 80-kW AC synchronous electric motor and the fuel tank installation being replaced by the battery pack. Although there are more high-voltage cables and wires for the electric vehicle than for a non-EV, Swenson points out that because they had been making an Altima Hybrid (through model year 2011), the workers at the Smyrna plant are familiar working with those electrical components. “The biggest challenge was transporting the LEAF on the line because it is smaller than the Altima and the Maxima,” he says. (The Altima is 191.5-in. long; the Maxima is 190.6-in. long; the LEAF is 175-in. long.)
There are approximately 300 people working in the Nissan battery plant, although it should be noted that it is heavily automated (there is an abundance of Mitsubishi SCARA robots throughout the facility), so presumably ramping up to high production volumes would be fairly straightforward.
The Nissan battery pack, which weighs approximately 600 lb., is flat, not cylindrical as is the case with many consumer electronics batteries. This facilitates cooling, which is critical for batteries (the configuration allows convection-style cooling rather than liquid-based; the convection process not only allows the battery module to be less complex, but it also reduces battery mass), as well as packaging: it is positioned in the vehicle under the floorboard.
Electrode material arrives in the Smyrna plant from Japan. It is in roll form. The roll is then cut into smaller rolls. The material is processed under humidity- and temperature-controlled conditions. The air is filtered and workers handling the rolls wear clean-room suits (a.k.a., “bunny suits”) to minimize the possibility of material contamination.
Once the rolls of materials are dried, they are cut into individual sheets that are about the size and thickness of a piece of 8.5 x 11-in. paper. There is a high-speed robot used to stack layers of electrode material with a polymer-based separator between the anode (+) and cathode (-). There are 68 layers in a cell. The ends of the material are ultrasonically welded, and then the stacked sheets are wrapped in an envelope-like aluminum foil container. An electrolyte—the liquid material that facilitates the passage of ions in the cells—is injected into the cell. Then the cells age for several weeks. The package is cut so that gases created by this chemical aging are released, then it is permanently sealed. The cells are tested, trimmed to final dimensions, charged, and then tested again. A cell has a capacity of 33 ampere hours (Ah).
A stack of four cells form a module. A module is placed in a steel case. Then the modules—48 of them—are assembled to form a 24 kilowatt-hour (kWh) battery pack for installation in the LEAF. That battery pack is capable of powering the car for approximately 84 miles (the mileage varies predicated on factors including driving behavior, temperature, and age of the battery).
The 2013 LEAF: Modifications Made
Although the LEAF has been available on the U.S. market since 2010, although there have been just model years 2011 and 2012, Nissan has modified the 2013 model in a number of ways. Brendan Jones, director, Nissan EV Infrastructure Strategy & Development, says that LEAF owners are a highly engaged and proactive group; “We’ve had lots of customer interaction and feedback—the most in Nissan’s history.”
The biggest change is that they’ve added a model to the lineup: the S, which has a base MSRP of $28,800, which means that with variously available incentives—governmental as well as those offered by some companies—it is possible to get a LEAF for less than $20,000.
The other two trims are the SV, which has an MSRP of $31,820, and the SL, which starts at $34,840.
Jones notes that there are those who were looking for a less expensive LEAF, which resulted in the S, and those who were looking for more amenities, which explains the leather seating on the SL. That said, they anticipate the greatest number of customers opting for the mid-grade SV trim.
So the customers asked for things like a light and a lock for the charge port door, and a release button for the door on the key fob.
In order to significantly increase the cargo capacity for the 2013 model, the on-board charger that had been in the back has been repositioned to the front of the vehicle: in there is 30-ft3 of space with the rear seat folded in the ’13 compared with 24-ft3 in the ’12.
The entry level S comes with a standard 3.6-kW onboard charger. It is available with an optional 6.6-kW onboard charger, standard on the other two models. The 6.6-kW charger reduces charging time via 220 V to approximately 4 hours for a full charge.
The SL comes standard—and it is optional for the other two—with a level-two Quick Charge Port that allows DC charging to 80% capacity in 30 minutes.
While all models have regenerative braking (when lifting from the accelerator or applying the brake pedal, the electric motor acts as a generator, sending energy to the battery), the SV and SL models have a “B-mode” (there are also “normal” and “Eco” mode) that provides more aggressive regenerative braking, to increase the amount of power sent back to the battery.
There are other modifications that help increase the range of the ’13 by as much as 15% compared to the previous vehicle. There is a more efficient HVAC system. They’ve blocked off portions on either side of the grille to improve aero, according to Mike Higginbotham of the Nissan Product Planning Dept. The coefficient of drag for the ’13 is 0.28, compared to 0.29 for the ’12.
Here is an interesting contrast: the LEAF SL has a photovoltaic solar panel on the spoiler, which is used to collect energy to help power vehicle accessories . . . yet all three trim levels have heated side-view mirrors.
The 2013 LEAF has been modified in various ways to help improve range as well as to address customer concerns. What’s interesting to note is that whereas midcycle enhancements generally occur after four years, the LEAF has been available on the U.S. market since December 2010.
One of the customer-requested changes to the LEAF was putting the battery percent of charge in the center meter display. While people who drive gasoline-powered vehicles may pay comparatively scant attention to their fuel gauge, drivers of EVs like knowing precisely how much charge they have.