Wood,an essential natural resource in human civilization,remains widely used despite advances in technology and material substitution.The surge in greenhouse gas emissions and environmental concerns accentuates the ne...Wood,an essential natural resource in human civilization,remains widely used despite advances in technology and material substitution.The surge in greenhouse gas emissions and environmental concerns accentuates the need for optimizing wood utilization.Material flow analysis is a powerful tool for tracking material flows and stocks,aiding resource management and environmental decision-making.However,the full extent of its methodological dimensions,particularly within the context of the wood supply chain,remains relatively unexplored.In this study,we delve into the existing literature on wood flow analysis,discussing its primary objectives,materials involved,temporal and spatial scales,data sources,units,and conversion factors.Additionally,data uncertainty,data reconciliation and crucial assumptions in material flow analysis are highlighted in this paper.Key findings reveal the significance of wood cascading and substitution effects by replacing non-wood materials,where they can reduce greenhouse gas emissions more than the natural carbon sink of forests and wood products.The immediate impact of short-term wood cascading might not be as robust as the substitution effect,with energy substitution showcasing better results than material substitution.However,it's crucial to note that these conclusions could experience significant reversal from a long-term and global perspective.Strategies for improving wood efficiency involve maximizing material use,advancing construction technologies,extending product lifespans,promoting cascade use,and optimizing energy recovery processes.The study underscores the need for standardized approaches in wood flow analysis and emphasizes the potential of wood efficiency strategies in addressing environmental challenges.展开更多
Base on the framework of material flow analsis (MFA) proposed by Eurostat, this paper collected related data and conducted a regional MFA for the Chengyang Districgt in Qingdao. The indicators such as Direct Materia...Base on the framework of material flow analsis (MFA) proposed by Eurostat, this paper collected related data and conducted a regional MFA for the Chengyang Districgt in Qingdao. The indicators such as Direct Material Input(DMI), Direct Material Consumption (DMC) and Exports are calculated or estimated for the period of year 1995 through 2004. Several derivable iudicators defining direct material productivity and material intenstiy are also evaluated and some valuable conclusions were drawn. DMI in absolute number increased from about 1645.9 kilotons in 1995to about 8052.5 kilotons in 2004. Imports contribute to about 47 to 69% of DMI, and the biggest component of imports is fossil fuel that approximatley accounts far 50% of imnports. DMI per capita of Chengyang District increased rapidly and reached 17. 4 tons in 2004. Compared with other five economies studied by WRI, material consumption intensity of Chengyang District is significantly lower than developed countries, which indicates that Chengyang District is still in a development stage The direct material productivity (actual GDP per DMI) increased 59.1% from 1995 to 2004 and has been higher than either of stadies in China, which indicates efficiency of resources utilization has improved obviously in Chengyang District. But there was significant increase in material input in the last decade, which shows that rapid increase of economy is highly dependent on requirement and consumption of natural resources. Therefore, in order to promote the sustainahility, it is essential to develop circular economy and improve utilization efficiency of resources.展开更多
Material Flow Analysis(MFA) is a crucial instrument for sustainable development and creating industrial ecology system.MFA studies could balance and analyze the sources,flows,and consumes of specific materials or subs...Material Flow Analysis(MFA) is a crucial instrument for sustainable development and creating industrial ecology system.MFA studies could balance and analyze the sources,flows,and consumes of specific materials or substances.The results of MFA studies could support the strategies or decisions making for energy, resource,and waste management,especially achieving sustainable resource management.At CSC,the dynamic simulating software,STELLA,is used to develop a MFA model for scenario analysis.CSC also uses the freeware STAN 2.0 as a tool for visualizing and simulating material flows and stocks.Case studies of greenhouse gases MFA for integrated steel works are conducted.The results showed that the carbon content of hot-metal is an important hidden flow for balance analysis,and the different GHG emission scenarios and mitigation action scenarios are assessed.In addition,the Iron-making GHG I/O MFA Model,based on worldsteel Global Steel Sector Approach(GSSA),is developed for calculating the CO_2 and energy intensity of coke making,sintering,and BF processes.This MFA model was used to analyze the CO_2 reduction potential for iron-making process.The cases conducted for MFA applications at CSC were such as greenhouse gas,zinc,etc.In the future,CSC is going to develop a 'CSC Environment Management and Decision Supporting System' which combine MFA,LCA(life cycle assessment),and environment risk assessment.This supporting system expects to promoting energy efficiency and best resource use,supporting environment policymaking,creating environmental information value,etc.展开更多
The method "Material Flow Analysis (MFA)" is one of the effective tools to study law and quantification of material flow between economic system and ecological system. On the national level, economy-wide material ...The method "Material Flow Analysis (MFA)" is one of the effective tools to study law and quantification of material flow between economic system and ecological system. On the national level, economy-wide material flow analysis has been published for a number of countries. However, published studies on the regional or local level are still very limited and a standardized method does not exist yet. On the basis of framework of Material Flow Analysis proposed by Eurostat, the paper collected related data and analyzed material input and output for the Chengyang district in Qingdao. The results showed that DMI (Direct Material Input) and TMR (Total Material Requirement) in absolute number increased about 3.6 and 3.9 times, respectively from 1995 to 2004. Fossil fuel and mineral contributed to about 50.3%-76.3% of DMI. Imports of material increased about 5.0 times and became the most important Contributor to DMI, which showed that local economic growth was highly dependent on resources from other regions and countries. DPO (Domestic Processed Output) and TDO (Total Domestic Output) represent slow increasing trend, and DPO contributed to 22.2%-58.1% of TDO, suggesting local hidden flows were of obvious effect on TDO. The biggest component of DPO is CO2, approximately accounting for 90% of DPO. The material productivity increased 57.7% in last decade, reflecting improvement of efficiency of resources utilization in some extent. However, compared to developed countries and regions, material productivity of Chengyang district was relatively low. Therefore, in order to promote the sustainability, it is essential to develop circular economy and enhance materials productivity.展开更多
Material dematerialization is a basic approach to reduce the pressure on the resources and environment and to realize the sustainable development. The material flow analysis and decomposition method are used to calcul...Material dematerialization is a basic approach to reduce the pressure on the resources and environment and to realize the sustainable development. The material flow analysis and decomposition method are used to calculate the direct material input (DMI) of 14 typical mining cities in Northeast China in 1995–2004 and to analyze the demateri- alization and its driving factors in the different types of mining cities oriented by coal, petroleum, metallurgy and multi-resources. The results are as follows: 1) from 1995 to 2006, the increase rates of the DMI and the material input intensity of mining cities declined following the order of multi-resources, metallurgy, coal, and petroleum cities, and the material utilizing efficiency did following the order of petroleum, coal, metallurgy, and multi-resources cities; 2) during the research period, all the kinds of mining cities were in the situation of weak sustainable development in most years; 3) the pressure on resources and environment in the multi-resources cities was the most serious; 4) the petro- leum cities showed the strong trend of sustainable development; and 5) in recent years, the driving function of eco- nomic development for material consuming has continuously strengthened and the controlling function of material utilizing efficiency for it has weakened. The key approaches to promote the development of circular economy of min- ing cities in Northeast China are put forward in the following aspects: 1) to strengthen the research and development of the technique of resources’ cycling utilization, 2) to improve the utilizing efficiency of resources, and 3) to carry out the auditing system of resources utilization.展开更多
The economic and ecological aspects of a social system are coherently linked and can be examined by its material and energy flows.In this study,we used the material flow analysis(MFA)to model the material input and ou...The economic and ecological aspects of a social system are coherently linked and can be examined by its material and energy flows.In this study,we used the material flow analysis(MFA)to model the material input and output of the Wujin District of Changzhou City,Jiangsu Province in China.It was revealed that:(1)total material input and material input per capita increased with economic development,while the total material out-put and material output per capita decreased consistently;(2)except for water,the total material input continued to increase.Input of solid materials grew faster than that of gaseous materials,while the total material output declined.The gas output accounted for the largest pro-portion of the output resulting in primary environmental pollution as burned fossil fuel;(3)water use in agriculture continued with an increasing trend while that in industrial and residential sectors decreased per capita.The total wastewater discharge and wastewater discharge per capita decreased with a faster decreasing rate of residential was-tewater discharge followed by industrial wastewater discharge;(4)material input per unit GDP fluctuated and material output per unit GDP decreased.A decreasing trend in both water use and wastewater discharge per unit GDP was disclosed.These results suggest that the efficiency of resource use in the Wujin District has improved.This weakened the direct link between economic development and environmental deterioration.Additionally,we discussed the harmonic development between environment and economy.Potential limitations of MFA’s application were also discussed.It is suggested that effective measures should be taken for the enforcement of cir-cular economic strategies and the construction of a resource-saving economy.展开更多
The process of economic activities is on the basis of tremendous material inputs.China has been discharging an enormous amount of waste,giving rise to a wide range of environmental impacts.The method of economy-wide m...The process of economic activities is on the basis of tremendous material inputs.China has been discharging an enormous amount of waste,giving rise to a wide range of environmental impacts.The method of economy-wide material flow analysis(EW-MFA)is one of the effective tools to examine the flow of materials entering physical economies,and recognize early environmental problems.Relevant researches are still at the early stage in China and most focus on material throughput but are rarely concerned about the utilization of recycling resource and environmental impact.Based on more than 3,000 items of data related,materials entering Chinese economy are classified into three types,and then the characteristics of material input and environmental impact are presented for the years 1990-2005 by using the indicators derived from EW-MFA.The Ratio of Recycled Material(RRM) is added as the new indicator in order to be in accordance with the need of circular economy being promoted in China.Results show that the great changes in the structure of material input cause the continuous increase of industrial solid waste emissions and the bogging down of material productivity.The RRM reveals that the utilization of recycling resources remains at a fairly low level in China.Finally,some weakness of EW-MFA is discussed according to the calculated results.展开更多
Consumers increasingly have worn-out batteries as electrical and electronic equipment with new technical developments are introduced into the market and quickly replace older models. As a result, large amounts of end-...Consumers increasingly have worn-out batteries as electrical and electronic equipment with new technical developments are introduced into the market and quickly replace older models. As a result, large amounts of end-of-life (EOL) or waste batteries are generated. Such batteries may contain a variety of materials that includes valuable resources as well as toxic elements. Thus, the proper recycling and management of batteries is very important from the perspective of resource conservation and environmental effect. The collection and recycling of EOL batteries is relatively low in South Korea compared to other countries, although an extended producer responsibility (EPR) policy was adopted for battery recycling in 2003. In this study, the management and material flow of EOL batteries is presented to determine potential problems and quantitative flow, based on literature review, site visits to battery recycling facilities, and interviews with experts in the Korea Battery Recycling Association (KBRA), manufacturers, and regulators in government. The results show that approximately 558 tons of manganese-alkaline batteries, the largest fraction among recycling target items, was disposed in landfills or incinerators in 2015, while approximately 2,000 tons of batteries were recovered at a recycling facility by simple sorting and crushing processes. By raising environmental awareness, more diverse and effective collection systems could be established for consumers to easily dispose of EOL batteries in many places. Producers, retailers and distributors in South Korea should also play an important role in the collection of EOL batteries from consumers. Lithium-ion batteries from many electronic devices must be included in the EPR system for resource recovery.展开更多
运用经济系统物质流分析方法(economy-wide material flow analysis,EW-MFA),分析1990—2003年我国国家层面资源利用与环境影响的2 600多个数据,得出1990—2003年间我国资源利用和环境影响特征.在选取EW-MFA传统分析指标基础上,结合我...运用经济系统物质流分析方法(economy-wide material flow analysis,EW-MFA),分析1990—2003年我国国家层面资源利用与环境影响的2 600多个数据,得出1990—2003年间我国资源利用和环境影响特征.在选取EW-MFA传统分析指标基础上,结合我国发展循环经济的需求和循环经济自身特点,增加了资源循环利用率新指标.研究表明:我国资源利用中直接物质投入量和国内物质输出量随GDP增长呈线性增长趋势.近年来,我国资源生产率出现低位下降,而循环利用率处于较低的水平,与日本的差距日益扩大;我国单位GDP的环境负荷略有下降,但经济的大规模发展造成环境总负荷上升.展开更多
Lithium-ion battery(LIB)is the key technology for climate change mitigation.The sustainability of LIB supply chain has caused widespread concern since the material utilization efficiency of LIB supply chain has not be...Lithium-ion battery(LIB)is the key technology for climate change mitigation.The sustainability of LIB supply chain has caused widespread concern since the material utilization efficiency of LIB supply chain has not been well investigated.This study aims to fill this research gap by conducting a dynamic material flow analysis of lithium in China from 2015 to 2021.Results indicate that within the temporal boundary,lithium flow and in-use stock grew significantly in China due to the rapid development of the EV market,with lithium flow in domestic production of basic chemicals increasing by 614%to 100 kt,end-use consumption increasing by 160%to 35 kt,and in-use stock increasing by 62%to 195 kt.China has been a net importer of lithium,of which cumulative imports and exports were 343 kt and 169 kt,respectively.In addition,103 kt of lithium was converted to inventories or was lost during the processing from 2015 to 2021.By optimizing inventory and processing,developing substitutes for lithium for non-battery applications,and improving lithium recycling,China's net import dependency of lithium could be reduced from 27%-86%to 0%-16%.Our study demonstrates that it is urgent to improve material utilization efficiency so that the lithium resource supply can be secured.展开更多
基金The China Scholarship Council finances this research (Grant number CSC202010220001)。
文摘Wood,an essential natural resource in human civilization,remains widely used despite advances in technology and material substitution.The surge in greenhouse gas emissions and environmental concerns accentuates the need for optimizing wood utilization.Material flow analysis is a powerful tool for tracking material flows and stocks,aiding resource management and environmental decision-making.However,the full extent of its methodological dimensions,particularly within the context of the wood supply chain,remains relatively unexplored.In this study,we delve into the existing literature on wood flow analysis,discussing its primary objectives,materials involved,temporal and spatial scales,data sources,units,and conversion factors.Additionally,data uncertainty,data reconciliation and crucial assumptions in material flow analysis are highlighted in this paper.Key findings reveal the significance of wood cascading and substitution effects by replacing non-wood materials,where they can reduce greenhouse gas emissions more than the natural carbon sink of forests and wood products.The immediate impact of short-term wood cascading might not be as robust as the substitution effect,with energy substitution showcasing better results than material substitution.However,it's crucial to note that these conclusions could experience significant reversal from a long-term and global perspective.Strategies for improving wood efficiency involve maximizing material use,advancing construction technologies,extending product lifespans,promoting cascade use,and optimizing energy recovery processes.The study underscores the need for standardized approaches in wood flow analysis and emphasizes the potential of wood efficiency strategies in addressing environmental challenges.
文摘Base on the framework of material flow analsis (MFA) proposed by Eurostat, this paper collected related data and conducted a regional MFA for the Chengyang Districgt in Qingdao. The indicators such as Direct Material Input(DMI), Direct Material Consumption (DMC) and Exports are calculated or estimated for the period of year 1995 through 2004. Several derivable iudicators defining direct material productivity and material intenstiy are also evaluated and some valuable conclusions were drawn. DMI in absolute number increased from about 1645.9 kilotons in 1995to about 8052.5 kilotons in 2004. Imports contribute to about 47 to 69% of DMI, and the biggest component of imports is fossil fuel that approximatley accounts far 50% of imnports. DMI per capita of Chengyang District increased rapidly and reached 17. 4 tons in 2004. Compared with other five economies studied by WRI, material consumption intensity of Chengyang District is significantly lower than developed countries, which indicates that Chengyang District is still in a development stage The direct material productivity (actual GDP per DMI) increased 59.1% from 1995 to 2004 and has been higher than either of stadies in China, which indicates efficiency of resources utilization has improved obviously in Chengyang District. But there was significant increase in material input in the last decade, which shows that rapid increase of economy is highly dependent on requirement and consumption of natural resources. Therefore, in order to promote the sustainahility, it is essential to develop circular economy and improve utilization efficiency of resources.
文摘Material Flow Analysis(MFA) is a crucial instrument for sustainable development and creating industrial ecology system.MFA studies could balance and analyze the sources,flows,and consumes of specific materials or substances.The results of MFA studies could support the strategies or decisions making for energy, resource,and waste management,especially achieving sustainable resource management.At CSC,the dynamic simulating software,STELLA,is used to develop a MFA model for scenario analysis.CSC also uses the freeware STAN 2.0 as a tool for visualizing and simulating material flows and stocks.Case studies of greenhouse gases MFA for integrated steel works are conducted.The results showed that the carbon content of hot-metal is an important hidden flow for balance analysis,and the different GHG emission scenarios and mitigation action scenarios are assessed.In addition,the Iron-making GHG I/O MFA Model,based on worldsteel Global Steel Sector Approach(GSSA),is developed for calculating the CO_2 and energy intensity of coke making,sintering,and BF processes.This MFA model was used to analyze the CO_2 reduction potential for iron-making process.The cases conducted for MFA applications at CSC were such as greenhouse gas,zinc,etc.In the future,CSC is going to develop a 'CSC Environment Management and Decision Supporting System' which combine MFA,LCA(life cycle assessment),and environment risk assessment.This supporting system expects to promoting energy efficiency and best resource use,supporting environment policymaking,creating environmental information value,etc.
基金Qingdao Agricultural University Research Fund (630707)
文摘The method "Material Flow Analysis (MFA)" is one of the effective tools to study law and quantification of material flow between economic system and ecological system. On the national level, economy-wide material flow analysis has been published for a number of countries. However, published studies on the regional or local level are still very limited and a standardized method does not exist yet. On the basis of framework of Material Flow Analysis proposed by Eurostat, the paper collected related data and analyzed material input and output for the Chengyang district in Qingdao. The results showed that DMI (Direct Material Input) and TMR (Total Material Requirement) in absolute number increased about 3.6 and 3.9 times, respectively from 1995 to 2004. Fossil fuel and mineral contributed to about 50.3%-76.3% of DMI. Imports of material increased about 5.0 times and became the most important Contributor to DMI, which showed that local economic growth was highly dependent on resources from other regions and countries. DPO (Domestic Processed Output) and TDO (Total Domestic Output) represent slow increasing trend, and DPO contributed to 22.2%-58.1% of TDO, suggesting local hidden flows were of obvious effect on TDO. The biggest component of DPO is CO2, approximately accounting for 90% of DPO. The material productivity increased 57.7% in last decade, reflecting improvement of efficiency of resources utilization in some extent. However, compared to developed countries and regions, material productivity of Chengyang district was relatively low. Therefore, in order to promote the sustainability, it is essential to develop circular economy and enhance materials productivity.
基金Under the auspices of Key Program of National Natural Science Foundation of China (No. 40635030)National Natu-ral Science Foundation of China (No. 40571041)
文摘Material dematerialization is a basic approach to reduce the pressure on the resources and environment and to realize the sustainable development. The material flow analysis and decomposition method are used to calculate the direct material input (DMI) of 14 typical mining cities in Northeast China in 1995–2004 and to analyze the demateri- alization and its driving factors in the different types of mining cities oriented by coal, petroleum, metallurgy and multi-resources. The results are as follows: 1) from 1995 to 2006, the increase rates of the DMI and the material input intensity of mining cities declined following the order of multi-resources, metallurgy, coal, and petroleum cities, and the material utilizing efficiency did following the order of petroleum, coal, metallurgy, and multi-resources cities; 2) during the research period, all the kinds of mining cities were in the situation of weak sustainable development in most years; 3) the pressure on resources and environment in the multi-resources cities was the most serious; 4) the petro- leum cities showed the strong trend of sustainable development; and 5) in recent years, the driving function of eco- nomic development for material consuming has continuously strengthened and the controlling function of material utilizing efficiency for it has weakened. The key approaches to promote the development of circular economy of min- ing cities in Northeast China are put forward in the following aspects: 1) to strengthen the research and development of the technique of resources’ cycling utilization, 2) to improve the utilizing efficiency of resources, and 3) to carry out the auditing system of resources utilization.
文摘The economic and ecological aspects of a social system are coherently linked and can be examined by its material and energy flows.In this study,we used the material flow analysis(MFA)to model the material input and output of the Wujin District of Changzhou City,Jiangsu Province in China.It was revealed that:(1)total material input and material input per capita increased with economic development,while the total material out-put and material output per capita decreased consistently;(2)except for water,the total material input continued to increase.Input of solid materials grew faster than that of gaseous materials,while the total material output declined.The gas output accounted for the largest pro-portion of the output resulting in primary environmental pollution as burned fossil fuel;(3)water use in agriculture continued with an increasing trend while that in industrial and residential sectors decreased per capita.The total wastewater discharge and wastewater discharge per capita decreased with a faster decreasing rate of residential was-tewater discharge followed by industrial wastewater discharge;(4)material input per unit GDP fluctuated and material output per unit GDP decreased.A decreasing trend in both water use and wastewater discharge per unit GDP was disclosed.These results suggest that the efficiency of resource use in the Wujin District has improved.This weakened the direct link between economic development and environmental deterioration.Additionally,we discussed the harmonic development between environment and economy.Potential limitations of MFA’s application were also discussed.It is suggested that effective measures should be taken for the enforcement of cir-cular economic strategies and the construction of a resource-saving economy.
基金supported by the 10th National Five-Year Program for Science and Technology Development of China(Grant No.2003BA614A-02)
文摘The process of economic activities is on the basis of tremendous material inputs.China has been discharging an enormous amount of waste,giving rise to a wide range of environmental impacts.The method of economy-wide material flow analysis(EW-MFA)is one of the effective tools to examine the flow of materials entering physical economies,and recognize early environmental problems.Relevant researches are still at the early stage in China and most focus on material throughput but are rarely concerned about the utilization of recycling resource and environmental impact.Based on more than 3,000 items of data related,materials entering Chinese economy are classified into three types,and then the characteristics of material input and environmental impact are presented for the years 1990-2005 by using the indicators derived from EW-MFA.The Ratio of Recycled Material(RRM) is added as the new indicator in order to be in accordance with the need of circular economy being promoted in China.Results show that the great changes in the structure of material input cause the continuous increase of industrial solid waste emissions and the bogging down of material productivity.The RRM reveals that the utilization of recycling resources remains at a fairly low level in China.Finally,some weakness of EW-MFA is discussed according to the calculated results.
文摘Consumers increasingly have worn-out batteries as electrical and electronic equipment with new technical developments are introduced into the market and quickly replace older models. As a result, large amounts of end-of-life (EOL) or waste batteries are generated. Such batteries may contain a variety of materials that includes valuable resources as well as toxic elements. Thus, the proper recycling and management of batteries is very important from the perspective of resource conservation and environmental effect. The collection and recycling of EOL batteries is relatively low in South Korea compared to other countries, although an extended producer responsibility (EPR) policy was adopted for battery recycling in 2003. In this study, the management and material flow of EOL batteries is presented to determine potential problems and quantitative flow, based on literature review, site visits to battery recycling facilities, and interviews with experts in the Korea Battery Recycling Association (KBRA), manufacturers, and regulators in government. The results show that approximately 558 tons of manganese-alkaline batteries, the largest fraction among recycling target items, was disposed in landfills or incinerators in 2015, while approximately 2,000 tons of batteries were recovered at a recycling facility by simple sorting and crushing processes. By raising environmental awareness, more diverse and effective collection systems could be established for consumers to easily dispose of EOL batteries in many places. Producers, retailers and distributors in South Korea should also play an important role in the collection of EOL batteries from consumers. Lithium-ion batteries from many electronic devices must be included in the EPR system for resource recovery.
文摘运用经济系统物质流分析方法(economy-wide material flow analysis,EW-MFA),分析1990—2003年我国国家层面资源利用与环境影响的2 600多个数据,得出1990—2003年间我国资源利用和环境影响特征.在选取EW-MFA传统分析指标基础上,结合我国发展循环经济的需求和循环经济自身特点,增加了资源循环利用率新指标.研究表明:我国资源利用中直接物质投入量和国内物质输出量随GDP增长呈线性增长趋势.近年来,我国资源生产率出现低位下降,而循环利用率处于较低的水平,与日本的差距日益扩大;我国单位GDP的环境负荷略有下降,但经济的大规模发展造成环境总负荷上升.
基金This study is sponsored by the National Key R&D Program of China(2019YFC1908501)National Natural Science Foundation of China(72122010,71774100,72088101,71810107001).
文摘Lithium-ion battery(LIB)is the key technology for climate change mitigation.The sustainability of LIB supply chain has caused widespread concern since the material utilization efficiency of LIB supply chain has not been well investigated.This study aims to fill this research gap by conducting a dynamic material flow analysis of lithium in China from 2015 to 2021.Results indicate that within the temporal boundary,lithium flow and in-use stock grew significantly in China due to the rapid development of the EV market,with lithium flow in domestic production of basic chemicals increasing by 614%to 100 kt,end-use consumption increasing by 160%to 35 kt,and in-use stock increasing by 62%to 195 kt.China has been a net importer of lithium,of which cumulative imports and exports were 343 kt and 169 kt,respectively.In addition,103 kt of lithium was converted to inventories or was lost during the processing from 2015 to 2021.By optimizing inventory and processing,developing substitutes for lithium for non-battery applications,and improving lithium recycling,China's net import dependency of lithium could be reduced from 27%-86%to 0%-16%.Our study demonstrates that it is urgent to improve material utilization efficiency so that the lithium resource supply can be secured.