摘要

With the expansion of the lithium ion (Li-ion) battery market, new materials for lithium ion cathodes are constantly being developed. Especially automotive applications require a decrease in production costs, which often means to increase the content of less expensive metals. However, these composition changes also affect the cathode properties and may also require considerable changes in the processing conditions. There are still considerable gaps regarding life cycle inventories for cathode materials as the availability of commercial process data is limited. The presented study had two main objectives: (1) quantifying the natural resource use for the production and recycling of five cathode materials for Li-ion batteries in a closed loop scenario based on data directly provided by industry and (2) assessing the impact of differences in composition, cathode material properties and production technology. An exergy-based method was employed to assess the cumulative resource use. To get a better view on the impact of the property differences of the cathode materials, resource consumption was expressed per kg, per kWh one cycle and per kWh over the cycle life. The latter was the actual functional unit. The results per kg of cathode were comparable for all (290-346 MJ(ex)/kg) but one (622 MJ(ex)/kg) of the cathode materials. Metal supply and energy use during cathode material production were the main drivers of natural resource use. Due to the diverging characteristics of the cathode materials the relative results in terms of the functional unit (0.39-0.70 MJ(ex)/kWh) differed considerably from the results per kg of cathode material. For example, while the resource use for one of the cathodes was relatively high per kg of material, it was similar to the resource use of two other cathode materials per kWh (cycle life). This implies that it is not sufficient to have good process data to compare the resource consumption of different cathode materials. The properties of the cathode materials, respectively the battery as a whole, have to be carefully determined in function of the application. Two of the cathode materials were developed with the target to reduce cost of feedstock metals while maintaining performance. Indeed, those two cathodes showed low resource use per kg (290-343 MJ(ex)) and per kWh (one cycle) (377-463 MJ(ex)).

  • 出版日期2014-12-1