Energy Consumption and Carbon Emission Analysis of Natural Graphite Anode Material for Lithium Batteries

Abstract

The production process of nature graphite anode material is divided into four stages, namely mining, beneficiation, purification and processing. Carbon emission and energy consumption during the whole process were quantified and analyzed in this study. The energy consumption and pollutant emissions in the production process were calculated in accordance with the method of life cycle assessment, and the carbon emission analysis was conducted by IPCC method. The life cycle energy consumption of 1 ton natural graphite anode material is 112.48GJ, and the processing stage contributes 41.71%. The results show that coke oven gas and raw coal are the main energy consumption in the whole life cycle of natural graphite anode material, which account for 32.33% and 23.41% of the total energy consumption, respectively. Furthermore, the carbon emission of 1 ton of natural graphite anode material is 5315.91kgCO2-eq, and mainly comes from raw coal and electricity which contribute 23.98% and 20.99% to the total carbon emission respectively, and CO2 is the largest carbon emission contributed 98.69% to total carbon emission. Finally, the carbon emissions are sensitive to the coke oven gas, raw coal, diesel and electricity, and insensitive to fuel oil.

Toward a life cycle inventory for graphite production

“…As identified previously, analysis of natural graphite production chain conducted by Gao et al (2018) has clearly demonstrated how significantly underestimated the energy demand and the GWP of the process is when using existing data embedded within the LCA databases.…”

“…An assessment by (Gao et al., 2018) (Figure 3b) is based on a mixture of primary and secondary data for a representative Chinese manufacturing process for natural flake graphite. This study distinguishes between various stages of graphite mining and processing including the final purification step necessary to upgrade graphite to battery‐grade purity and post‐processing into coated graphite.…”

Life Cycle Modelling of Extraction and Processing of Battery Minerals—A Parametric Approach

“…Gao et al [33] calculated the carbon emissions for anode material production in China using natural graphite and found this value to be 5.3 kg CO 2 e/kg of anode material. Their results indicate that the graphite mining and surface modification stages are significant drivers of the energy and, consequently, the emissions compared to the graphite beneficiation and purification stages.…”

“…The production of graphite occurs via two routes, namely either natural and synthetic [35]. The base inventory for natural graphite is obtained from Zhang et al [33] and Gao et al [82], while the inventory for synthetic graphite is provided by Dunn et al [35]. We approximate the energy used in mining and concentration of natural graphite ores to follow an inverse relationship provided by Valero and Valero [72] and calibrated with data from Gao et al [33] and Zhang et al [82].…”

“…The base inventory for natural graphite is obtained from Zhang et al [33] and Gao et al [82], while the inventory for synthetic graphite is provided by Dunn et al [35]. We approximate the energy used in mining and concentration of natural graphite ores to follow an inverse relationship provided by Valero and Valero [72] and calibrated with data from Gao et al [33] and Zhang et al [82]. Due to low data resolution on converting graphite flakes into batterygrade, downstream processing of natural graphite flakes into battery-grade is excluded.…”