Life Cycle Analysis of AA Alkaline Batteries

Abstract

From energy and CO2 footprint perspectives, this study focuses on the Life Cycle Analysis (LCA) of AA alkaline batteries considering options other than landfill namely downcycling or, more ambitiously, recycling/remanufacturing. With the exception of lead-acid batteries that are recycled intensively in an energy-efficient manner, many types of batteries are not recycled and are disposed of via traditional disposal routes. Currently, there is lack of economical incentive given that available processes used in recycling batteries to reclaim metals require 6-10 times more energy than extracting/refining those metals from ores. Some processes (e.g., pyrometallurgical) require large capital investment and use large amounts of energy. For AA batteries, current recycling techniques involve 1) burning off the plastic wrapper, 2) batteries are shredded, and 3) melted where metals segregate into layers according to their respective densities, and 4) each molten metal layer is then collected.This study addresses the feasibility of recycling alkaline batteries, as they are the most common dry batteries as well as being more benign as compared with other types such as lithium-ion or Ni-cadmium. From energy and CO2 footprint perspectives, this study makes a case for downcycling or even recycling/remanufacturing (depending on the material of the separated components) for the zinc metal, manganese oxide concentrates, and other components for recycling/reuse in an efficient/environmentally-friendly manner. Life cycle analysis (LCA) findings suggest that, if technology is developed so that the cathode and anode materials are recycled/reused, there will be significant recovered energy and CO2 values. For a world annual production estimate of 4 billion AA alkaline batteries, the EOL potential findings estimate energy savings and CO2 footprint reduction of about 6.2*1015 J and 3.75*108CO2 kg, respectively.