New Leaf pack stock dismantling

New Leaf pack stock dismantling

Recently, Nikkei Technology has developed a "Real Dismantling Lab" project, which initiated by the actual development conference hosted by Nikkei xTECH and the Nikkei BP Research Institute. As part of the project, the decomposition study of the new LeafEV model was implemented in February 18th.

With the participation of the automotive industry such as electric vehicles, autonomous driving, and sharing era, the market environment is undergoing tremendous changes. How to get the most out of the new competitive environment is the latest intelligence. Feel the rudiment of the future car, find out what the company can get involved in, or understand the limitations of its own company, and find opportunities to enter new markets. It is difficult for a company to conduct such analysis alone. Nikkei technology has assembled a group of related companies to conduct in-depth analysis by understanding each other's insights and findings. This article is part of the Li ion second battery pack report for the driving force part of Leaf new EV model decomposition series.

Starting from the first generation, the Leaf Battery Pack is a natural cooling system with a traditional closed structure. Nissan has adopted a soft-pack type battery with excellent heat dissipation. The company is confident in the battery pack structure that does not require active air-cooling or water-cooling.

The battery and battery modules of the new model manufactured by Nissan Motor and NEC's joint venture Automotive Energy Supply Company (AESC). Since its inception in 2007, AESC has been specializing in the development of flexible packaged batteries and has been providing batteries and battery modules from the first generation of Leaf. However, AESC will sold to the Chinese investment fund GSRCapital. Nissan will focus on the development of next-generation batteries, and the battery and module procurement policy will shift to a policy of sourcing from large suppliers. Therefore, in the future Nissan electric vehicles, the adoption ratio of LG Chem and Panasonic's battery modules will increase.

Battery modules of other battery manufacturers require a cooling device for most of the actual vehicle. However, the battery module made by AESC on this new Leaf model can said to be a master of natural cooling. *1)

*1) Nissan Motor Co., Ltd. invests in the development of all-solid-state batteries, promotes the development of Li-ion secondary batteries composed of all-resin batteries, etc. According to this series of measures, it predicted that Nissan might continue to adopt the battery pack system of natural air-cooling.

Evolving toward a simpler structure

The most intuitive way to open the battery pack is that the structure is quite simple. The battery pack consists of a battery module, a junction box, a circuit breaker called a "service. Connector" and a battery controller.

The new battery pack Pack consists of 24 modules and 8 batteries (192 batteries) placed in a stainless-steel case of one module. The battery pack weighs 303 kg and has a total voltage of 350V. The first-generation Leaf (ZE0) consists of four modules and one module, and the entire battery pack consists of 48 modules. In addition, the difference is that the outer metal shell of the first-generation Leaf module belongs to the whole cover, and the module metal shell of the new Leaf is open to the four corners, and the eight batteries in the module can be seen from the outside.

Although the external dimensions of the battery pack are almost the same, the Pack capacity has increased by 1.6 times from the 24th generation of the first generation to the 40Kwh energy density. Surprisingly, despite the significant increase in volumetric efficiency, it is still only possible with natural cooling.

In addition, the first generation of Leaf warranty content guaranteed for 5 years or 100,000 kilometers. In December 2015, the micro-reform capacity increased to 30Kwh, and the warranty content extended to 8 or 160,000 kilometers. The extension of the new Leaf warranty for 40Kwh capacity will continue. It said that this is the result of excellent results in controlling and preventing battery attenuation by using the actual data of the first-generation Leaf.

The new model battery and module manufactured by AESC and battery controller manufactured by Kangnai, junction box is equipped with relays made by Panasonic equipment (now Panasonic Switch Technology). The high-voltage cable manufactured by Sumitomo Electric.

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