Life Cycle Assessment Of Electric Vehicle Power Battery

In recent years, our government has increased the investment to the new energy vehicledevelopment, promotion and application, set and issued a series of policies to support andguide the development of the electric car industry, the aim is to reduce oil resourceconsumption, improve urban air quality, and promote the traditional vehicle industrytransformation. Power battery is one of the key components of electric vehicle, at the sametime of rapid development, however, the power battery have caused some damage to theenvironment throughout the entire life cycle. Thus reduce the resources, energy consumptionand environmental emissions in life cycle of power battery has an important significance toimproving the electric vehicle environment performance and sustainable development.Life Cycle Assessment (LCA) is considered to be one of the most effective tool toevaluate the products impact on environment in the20th century, it can be used to quantifyand analyze product life cycle resources, energy consumption and environmental emissionssynthetically, and give conclusions and recommendations on environmental performanceimprovements based on assessment. Its theoretical approaches and ideas have become coremethods and ideas in a variety of regulations and policies of developed countries, and widelyused in all kinds of regulations and policies.This paper first build the power battery system model and its LCA model through in-depth study the LCA theory, then analyze and evaluate the energy consumption andenvironmental emissions of power battery "cradle to use” stage(transport stage of powerbattery not included)and recycle stage,"cradle to use” stage include "cradle to gate” stage andbattery use stage. The results shows, in "cradle to use” stage, the energy consumption of thelithium-ion battery and nickel-metal battery are0.41MJ/km and0.82MJ/km, greenhouse gasesemission are0.10kgCO2-eq/km and0.14kgCO2-eq/km, the energy consumption of lithium-ion battery and nickel-metal battery in use stage is36%and57%of the total energy, the greenhouse gases emission is80%and81%of the total; the energy consumption and emissionsof raw materials extraction processing phase is about90%of total in “cradle to gate” stage. Inpower battery recycle stage, assuming that recycling rate of nickel, aluminum, steel, nickelhydroxide, lithium carbonate are60%、70%、90%、60%、80%respectively, the energyconsumption and emissions of “cradle to gate” stage can be reduced about50%-60%.According to the results of sensitivity analysis, if charging and discharging efficiency ofthe NiMH battery model increased by20%, its energy consumption of use phase will bedecreased by60%, and the influence degree to use phase energy consumption is3-6times ofthe weight-energy factor; in “cradle to gate” stage, the energy consumption and emissions ofusing plastic shell is77%and85%lower than using aluminum shell; increase the proportionof wind power, nuclear power, and hydropower and other clean power can improve use phaseenvironmental performance of power battery; for NiMH power battery, the most significantrecycle-benefit of energy and GHGs emission is aluminum, followed by nickel, nickelhydroxide, steel.