Alkaline Batteries

Material Composition Assumptions

The default reference product is a 4-pack of AA alkaline batteries weighing approximately 0.10 kg (100 g) total (approximately 23 g each plus packaging), composed of:

• Manganese dioxide (MnO2) cathode: Electrolytic manganese dioxide mixed with graphite conductive additive, approximately 40% of cell mass. Manganese is primarily mined in South Africa, Gabon, Australia, and China.
• Zinc anode: Zinc powder (high-purity) gel anode with potassium hydroxide (KOH) electrolyte, approximately 20% of cell mass.
• Steel casing: Nickel-plated steel can and bottom plate, approximately 25% of cell mass. Provides structural integrity and acts as the cathode current collector.
• Separator and seals: Non-woven cellulose or synthetic separator, nylon seal, and brass current collector nail, approximately 10% of cell mass.
• Packaging: PVC or PET blister pack with printed cardboard backing, approximately 15-20 g per 4-pack.

Alkaline batteries are a mature, commoditized product with well-established supply chains. The zinc-manganese dioxide chemistry has been the dominant primary (non-rechargeable) battery technology since the 1960s.

Manufacturing Geography

Alkaline battery production is moderately concentrated:

• USA: Duracell (Bethel, CT) and Energizer (multiple US plants) manufacture the majority of batteries sold in North America.
• China: Major exporter of private-label and economy alkaline batteries. Largest global producer by volume.
• Japan: Panasonic (formerly Matsushita) produces alkaline cells for Asian and global markets.
• EU: Belgium (Duracell Europe), Germany, and other sites serve European markets.
• Grid intensity (USA): 390 gCO2e/kWh (IEA 2024). Used as baseline since major branded production is US-based.
• Grid intensity (China): 565 gCO2e/kWh (IEA 2024). For economy/export-oriented production.
• Rationale: Cell assembly is moderately automated and uses electricity for mixing, filling, crimping, and testing. Upstream material refining (zinc smelting, electrolytic MnO2 production) is the dominant emission source.

Regional Variation

Manufacturing Region	Grid Intensity	Estimated CCI Score	Adjustment vs Default
USA (default)	~390 gCO2e/kWh	3.0 kgCO2e	Baseline
China	~565 gCO2e/kWh	3.3 kgCO2e	+10%
Japan	~460 gCO2e/kWh	3.1 kgCO2e	+3%
EU average	~300 gCO2e/kWh	2.8 kgCO2e	-7%
Belgium	~160 gCO2e/kWh	2.6 kgCO2e	-13%

Note: Scope 3 (upstream mining and refining) dominates at 73% of total emissions, so grid variation has limited effect on the overall score.

Provenance Override Guidance

A supplier or brand may override the default CCI score by submitting:

1. Product Carbon Footprint (PCF) per ISO 14067 covering raw materials through packaged product.
2. Metal sourcing data: Zinc and manganese sourcing with verified refinery emissions data. Electrolytic zinc and MnO2 from hydro-powered refineries can have significantly lower emissions.
3. Factory energy data: Renewable electricity procurement at assembly facilities.
4. Packaging data: Reduced or recyclable packaging (cardboard-only vs. PVC blister) can lower packaging-stage emissions.

Methodology Notes

• CCI score of 3 kgCO2e per 4-pack represents a conservative estimate consistent with Parsons (2007) range of 2.4-3.5 kgCO2e and Dolci et al. (2016) comparative data. The score reflects US-based manufacturing with global material sourcing.
• Scope breakdown: Scope 3 dominates at 73% (2.2 kgCO2e), driven by zinc and manganese mining/refining, steel production, and packaging materials. Scope 2 is 17% (0.5 kgCO2e) from factory electricity. Scope 1 is 10% (0.3 kgCO2e) from on-site thermal processes.
• Functional unit: One 4-pack of AA alkaline batteries (~100 g total), cradle to gate.
• Use-phase: Not applicable — batteries are consumed during use with no additional energy input.
• End-of-life: Alkaline batteries are landfill-safe in most jurisdictions but contain recoverable zinc and steel. Recycling rates remain low (~5% in the US). End-of-life impacts excluded.
• Comparison context: On a per-kWh-delivered basis, disposable alkaline batteries are roughly 50-100x more carbon-intensive than rechargeable lithium-ion equivalents, underscoring the value of rechargeable alternatives for high-drain applications.