日产汽车电池厂探秘

    今天的汽车工厂不再像上世纪的先辈那样嘈杂脏乱。在这个方面，位于美国田纳西州士麦那的日产（Nissan）全新锂电池工厂以其实验室般的整洁环境更进一步。

    这家工厂价值3亿美元，配备了100名工人。他们许多身着白色工作服，在干净房间里的自动化机器旁边，忙着生产用于电动汽车日产聆风（Leaf）的电池包。聆风最初销量不佳，如今却由于日产今年1月起实行的大幅折扣而渐有起色。

    日产电动汽车战略的负责人布兰登•琼斯说：“聆风的买家热情得让人难以置信。”他表示，聆风正在发展狂热的追随者。“从来没有一款车像聆风一样，有众多车主给我们打电话、跟我们聊车、给我们提出改进建议。”

    聆风的车身同Altima和Maxima一起，在附近的生产线进行组装——不过聆风没有引擎和汽车油箱，取而代之的是重达600磅的电池包和电动马达。在美国制造聆风和配备的电池可以维持较低的运输成本。此举也表达了日产对美国于2007年借款14亿美元支持此项目的感激之情。

    不过平心而论，如果当初不是因为加利福尼亚州政府要求（而且如果美国不允许加利福尼亚州如此要求）提高零排放车辆的销量来遏制尾气污染，日产就不会制造电池或电动汽车了。上个月，汽车行业向美国环保署（U.S. Environmental Protection Agency）请愿，希望政府取消到2025年销售140万辆电动、混合动力和燃料电池汽车的要求。

    锂电池技术是安全问题的争论焦点。尽管这种电池尽管功能强大，但却会产生大量热量。因此制造过程需要一丝不苟，而且可能很棘手。工作中的锂电池必须谨慎处理，以防止产生导致波音787梦想客机最近被禁飞的类似问题。

    日产的电池在钢铁模组间加入了一系列层压薄板，而且置于客舱的下部。它可以通过空气散热，而其他厂商的电池则需要使用液体冷却剂。

    日产的本国头号竞争对手丰田（Toyota）在油电混合动力车上并没有采用锂电池技术，暗示着在其他类型的电池化学技术上，他们预见到了突破性的进展。

    Modern auto factories hardly resemble their noisy, dirty, chaotic forebears of the previous century. Nissan Motor Co.'s new lithium-ion battery plant in Smyrna, Tenn. goes one step further with an atmosphere reminiscent of a laboratory.

    The $300 million factory, which operates with 100 workers --many clad in white smocks, toiling away amid robotized machines in clean rooms -- manufactures battery packs for the electric Nissan Leaf. The Leaf's initial slow sales are perking up, thanks to steep discounting announced by Nissan in January.

    "The people who buy the Leaf are incredibly enthusiastic," said Brendan Jones, Nissan's (NSANY) head of electric-vehicle strategy. Leaf, he said, is developing a cult-like following. "We've never sold a vehicle that has had so many of its owners calling, talking, suggesting ideas for improvements."

    The Leaf body is assembled nearby on a production line along with Nissan Altima and Maxima -- but instead of an engine and gas tank, it gets a 600-pound battery pack and electric motor. Building the Leaf and its battery in the U.S. keeps transportation costs low and reflects appreciation for $1.4 billion the U.S. lent to Nissan in 2007 for the project.

    Fair's fair, after all, since Nissan mightn't be manufacturing batteries or electric vehicles if California didn't mandate (and the U.S. didn't permit California to mandate) the sale of a greater and greater number of emission-free vehicles in the state to combat smog. The auto industry last month petitioned the U.S. Environmental Protection Agency to drop the requirement to sell 1.4 million electric, plug-in hybrid and fuel cell vehicles by 2025.

    Lithium-ion technology has been the center of debates over safety because the batteries, while powerful, tend to generate quite a bit of heat. The manufacturing process, therefore, is precise and can be tricky. The batteries while in operation must be managed carefully in order to prevent problems of the type that recently grounded the Boeing (BA) 787 Dreamliner.

    Nissan's battery design, a series of laminated sheets inside steel modules, is buried below the passenger cabin. Its heat is dissipated by air; designs by other manufacturers require a liquid coolant.

    Nissan's top Japanese competitor, Toyota (TM), has avoided lithium-ion technology in its gas-electric hybrids, hinting that it foresees a breakthrough in some other type of battery chemistry.