With the increasing severity of global warming, urban pollution, and fossil fuel shortages, many countries have adopted strategies to replace traditional internal combustion engine vehicles with new energy vehicles. Lithium-ion batteries have emerged as a primary power source for these vehicles due to their environmental friendliness and excellent electrochemical performance. However, the manufacturing process of EV power batteries itself consumes resources and energy, contributing to greenhouse gas emissions and other environmental impacts. Therefore, conducting carbon footprint assessments for these batteries is a critical step toward achieving green and low-carbon development in the new energy vehicle industry. Carbon footprint, quantified using life cycle assessment methods, represents the total greenhouse gas emissions directly or indirectly generated by a product throughout its life cycle. As carbon footprint gradually plays a key role in international trade, rising “carbon barriers” are becoming new rules in the global automotive market. For instance, the EU Battery Regulation, effective from August 2023, mandates that starting July 2024, EV power batteries must declare their product carbon footprint, with non-compliant products facing market restrictions or economic penalties. This makes establishing a carbon footprint system for China EV batteries an urgent and unavoidable task for companies targeting the European market.
In terms of industry development, the China EV battery market has experienced significant growth driven by the expansion of new energy vehicles. According to industry data, China’s new energy vehicle sales reached 12.866 million units in 2024, accounting for 70.5% of global sales. Exports also saw an increase, with 1.284 million units exported in 2024. For EV power batteries, cumulative sales in China hit 791.3 GWh by 2024, with lithium iron phosphate (LFP) batteries dominating at 74.6% and nickel-cobalt-manganese (NMC) ternary batteries at 25.3%. Europe, lacking local battery manufacturers, has become the largest overseas market for China EV batteries, with their share in European installations rising from 15.3% in 2021 to 43.5% in 2024. Leading global companies in this sector include CATL and BYD from China, which together hold a substantial market share. To address environmental concerns, many China EV battery manufacturers have initiated low-carbon or zero-carbon plans, such as building zero-carbon factories and promoting recycling initiatives, highlighting the importance of carbon footprint reduction in the EV power battery lifecycle.
Carbon footprint, derived from the concept of “ecological footprint,” quantifies the total greenhouse gas emissions in terms of CO2 equivalent from human activities, such as production and consumption. For products like EV power batteries, carbon footprint evaluation typically covers the entire life cycle, including raw material extraction, manufacturing, transportation, use, and end-of-life treatment. The system boundaries can vary, such as “cradle-to-grave” for consumer products like batteries or “cradle-to-gate” for intermediate products. A general formula for carbon footprint (CF) calculation is:
$$ CF = \sum_{i=1}^{n} (AD_i \times EF_i) $$
where \( AD_i \) represents the activity data (e.g., energy consumption) for process \( i \), and \( EF_i \) is the emission factor for that process. For EV power batteries, this involves summing emissions across stages like material production, cell manufacturing, and recycling.
Internationally, several standards guide product carbon footprint assessment. Key among them are PAS 2050, the GHG Protocol, and ISO 14067. PAS 2050, the first global standard for product-level carbon footprint, provides detailed guidance, including formulas for delayed emissions. For example, the weighted impact of delayed emissions can be expressed as:
$$ CF_{delayed} = \sum_{t} E_t \times (1 + r)^{-t} $$
where \( E_t \) is the emission at time \( t \), and \( r \) is the discount rate. The GHG Protocol offers comprehensive classifications, such as dividing data into direct measurements, activity data, and emission factors, while ISO 14067, derived from PAS 2050, has weaker operational guidance, such as lacking specific methods for delayed emissions beyond a 10-year threshold. These standards form the basis for evaluating the carbon footprint of China EV batteries, but adaptations are needed to address local contexts.
In China, the carbon footprint standard system for EV power batteries is still evolving. Currently, there are 21 relevant standards, predominantly group standards, with few covering components like anodes, separators, or battery management systems. The table below summarizes some key domestic standards related to China EV battery carbon footprint:
| Standard Name | Code / Status | Category | Issuing Body |
|---|---|---|---|
| Guidance for Carbon Footprint Assessment of Lithium-ion Battery Products | T/DZJN 77-2022 | Group Standard | China Electronic Energy Saving Technology Association |
| Guidance for Carbon Footprint Assessment of Lithium-ion Battery Products – Part 2: Cathode Material – LFP | T/DZJN 216-2023 | Group Standard | China Electronic Energy Saving Technology Association |
| Guidance for Carbon Footprint Assessment of Lithium-ion Battery Products – Part 3: Cathode Material – NMC | T/DZJN 201-2023 | Group Standard | China Electronic Energy Saving Technology Association |
| Guidance for Carbon Footprint Assessment of Lithium-ion Battery Products – Part 4: Anode Material | T/DZJN 202-2023 | Group Standard | China Electronic Energy Saving Technology Association |
| Requirements for Carbon Footprint Accounting and Reporting – Lithium Carbonate | T/FSYY 0034-2021 | Group Standard | Foshan High-Tech Application Research Association |
| Greenhouse Gases – Product Carbon Footprint Quantification Methods and Requirements – Power Batteries | Under Development | National Standard | State Administration for Market Regulation |
These standards generally follow international methodologies but lack specificity for China’s regional and industrial characteristics. As export and supply chain demands grow, there is an urgent need to enrich and establish detailed product category rules for EV power batteries.
Research on the carbon footprint of EV power batteries has advanced significantly, focusing on factors like material systems, manufacturing technologies, cycle life, electricity structure, system boundaries, and recycling. For material systems, studies compare different battery chemistries. For instance, LFP batteries generally show lower carbon footprints than NMC batteries. The global warming potential (GWP) for various EV power battery types can be modeled as:
$$ GWP = \sum_{j} (M_j \times EF_{M_j}) + E_{manuf} \times EF_{elec} $$
where \( M_j \) is the mass of material \( j \), \( EF_{M_j} \) is its emission factor, \( E_{manuf} \) is the energy consumed during manufacturing, and \( EF_{elec} \) is the emission factor of electricity. Research indicates that silicon nanowire-based NMC batteries have the highest carbon footprint, while iron sulfide solid-state batteries have the lowest. The table below summarizes carbon footprint comparisons for different China EV battery material systems:
| Battery Type | Carbon Footprint (kg CO2 eq/kWh) | Notes |
|---|---|---|
| LFP | 80-120 | Lower due to abundant iron and phosphorus |
| NMC | 120-180 | Higher due to cobalt and nickel extraction |
| Solid-state (Lithium-sulfur) | 199 | Based on laboratory-scale production |
| Lithium Metal Polymer | 150-200 | Varies with electricity mix |
In terms of manufacturing technologies, processes using brine-based lithium extraction show lower emissions than ore-based methods. For example, battery-grade lithium carbonate from brine has a GWP of approximately 3-5 kg CO2 eq/kg, compared to 10-15 kg CO2 eq/kg from spodumene ore. This impacts the overall carbon footprint of China EV batteries, as expressed in the formula for cradle-to-gate emissions:
$$ CF_{cradle-to-gate} = CF_{material} + CF_{processing} + CF_{assembly} $$
Cycle life also plays a crucial role; longer lifetimes reduce the carbon footprint per functional unit. The relationship can be described as:
$$ CF_{per cycle} = \frac{CF_{total}}{N_{cycles}} $$
where \( N_{cycles} \) is the number of charge-discharge cycles. Studies using Monte Carlo simulations show that cycle efficiency is a key determinant, with higher efficiency reducing lifecycle costs and environmental impacts.
Electricity structure is another critical factor, as the carbon intensity of grid electricity varies by region. For instance, in European countries with high renewable shares, such as Sweden, battery manufacturing emissions are lower. The carbon footprint from electricity use in battery production can be calculated as:
$$ CF_{elec} = E_{prod} \times EF_{grid} $$
where \( E_{prod} \) is the production energy and \( EF_{grid} \) is the grid emission factor. In China, optimizing the electricity mix could reduce the carbon footprint of EV power batteries by over 13% by 2030.
System boundaries in carbon footprint studies often differ, with few covering the full “cradle-to-grave” scope due to data limitations. Research on recycling shows that using recycled metals can cut production-phase emissions by 50-60%. The net carbon benefit of recycling can be quantified as:
$$ CF_{recycling} = CF_{virgin} – CF_{recovered} + E_{recycle} \times EF_{elec} $$
where \( CF_{virgin} \) is the footprint of virgin materials, \( CF_{recovered} \) is the reduction from recovered materials, and \( E_{recycle} \) is the energy for recycling processes. For example, lead-acid batteries show up to 50% lower environmental impacts with recycling, while advancements in hydrometallurgical recycling for lithium-ion batteries avoid emissions associated with graphite production.
Despite progress, carbon footprint assessment for China EV batteries faces several challenges. The standard system is underdeveloped, with limited coverage of product category rules and insufficient authority for some standards. Data availability is problematic, as lifecycle data spans multiple enterprises and countries, leading to inconsistencies and inaccuracies. Reliance on international databases may not reflect China’s actual conditions, complicating accurate核算. Technically, allocating emissions in multi-product systems remains unresolved, and domestic digital tools for carbon footprint calculation are nascent. Talent shortages are also evident, as carbon footprint assessment requires interdisciplinary expertise in materials, processes, and emissions核算, which is not yet fully addressed in China’s education system.
To address these issues, we propose the following suggestions for advancing carbon footprint research and systems for EV power batteries. First,健全 the carbon footprint核算 standard system by expanding coverage to mainstream batteries like LFP and NMC, as well as emerging technologies such as solid-state and hydrogen storage batteries. This should involve coordinated development of national, local, industry, and group standards. Second, strengthen the construction of localized carbon databases to provide accurate emission factors and activity data specific to China’s context. This is essential for calculating the true carbon footprint of China EV batteries and supporting policy decisions. Third, enhance supply chain collaboration, as regulations like the EU Battery Requirement emphasize traceability and low-carbon procurement. Companies across the EV power battery产业链 must adopt green practices and participate in carbon reduction initiatives. Fourth, accelerate international cooperation by engaging in global standard-setting and mutual recognition agreements, facilitating the entry of China EV battery products into international markets. By implementing these measures, China can better navigate carbon barriers and promote sustainable development in the EV power battery industry.
In summary, the carbon footprint of China EV batteries is a multifaceted issue influenced by material choices, manufacturing processes, and lifecycle management. Through standardized assessments, data improvements, and international engagement, the industry can achieve significant reductions in greenhouse gas emissions, contributing to global climate goals and enhancing the competitiveness of China EV battery products in the global market.