Comparative Study On Life Cycle Assessment Of Li-ion Power Battery And Pure Electric Vehicle

The energy and environmental crisis and the opportunities of the times have promoted the rapid growth of battery electric vehicle(BEV)sales,reaching 1.115 million in 2020,which will continue to rise in the future based on policy promotion.From the perspective of the use stage,BEVs consume electric energy without environmental emissions.However,from the point of view of the life cycle,the production of electric energy and the manufacture of vehicle still bring many problems such as energy consumption and environmental impact.In the context of high-speed development and potential impact,clarifying the relationship between development and impact has prompted this study to conduct a comparative study on BEVs of assembling different lithium-ion power batteries from the horizontal perspective,and to conduct vertical comparisons and prediction analysis of environmental impact between BEVs and other vehicles with different power systems.The results have a certain reference value of green development for motor-dom.This paper is supported by the Innovation Capability Support Program of Shaanxi(Program No.2021TD-28)and the Key Research and Development Program of Shaanxi(Program No.2019ZDLGY15-07).In this study,based on the installed capacity selects lithium iron phosphate(LFP),lithium nickel cobalt manganate(NCM),lithium manganate(LMO),lithium titanate(LTO)and lithium sulfur(Li-S)batteries and from sales volume selects BYD E5 as the research objects.Firstly,a horizontal comparative study is conducted on different lithium batteries assembled for BEVs.The life cycle is divided into five stages: raw material acquisition,manufacturing,assembly,operation and use,and scrap recycling,and the mathematical matrix model and Ga Bi model of each stage is successively established.Then,the platform outputs the result lists of energy consumption,resource and pollutant discharge of life cycle.The CML2001 is used to normalize the impact results,comparing the results from the two perspectives of batteries itself and batteries assembled with BEV.According to the comparison results,the sensitive factors of charge discharge efficiency and battery energy density are selected to analyze the sensitivity.Finally,a longitudinal study of BEVs is carried out.Combined with the "Energy-saving and New Energy Vehicle Technology Roadmap 2.0" to select Battery Electric Vehicle(BEV),Plugin Hybrid Vehicle(PHEV),Fuel Cell Vehicle(FCV)conducts life cycle comparative research and predictive analysis.The results show that,from the perspective of power battery,BEV assmble with LTO battery has the highest comprehensive environmental impact at the stage of raw material acquisition stage,followed by assmbling Li-S,NCM,LFP and LMO battery.From the perspective of BEV assembling different power batteries: in terms of mineral resource depletion,the BEV assembling with LTO battery life cycle consumption is the largest,and assembling with lithium sulfur battery vehicle is the least;in terms of fossil energy consumption,the consumption of BEV assembling with LTO battery is the most,and assembling with NCM battery is the least;in terms of comprehensive environmental impact,the sequential results obtained by assembling different battery types in BEV: LTO>LMO>LFP>Li-S>NCM.The sensitivity analysis shows that the impact range of charge and discharge efficiency on the comprehensive environment is 6.67%~8.27%,and the impact range of battery energy density is 1.10%~2.64%.Finally,the comparison results of vehicles with different power systems show that: the current comprehensive environmental impact is: BEV>FCV>PHEV.In the 2020-2035 forecast results: the FCV environmental emissions will be lower than PHEV in 2029;BEV emissions will reach the same level as PHEV in 2034,and will have always been higher than FCV environmental emissions.BEV will become a sustainable development vehicle next only to FCV in the future.