Life Cycle Assessment of Rechargeable Batteries in Portable Devices

Rebecca Lankey, Francis McMichael, Chris Hendrickson and Lester Lave, Green Design Initiative

Introduction

The use of rechargeable batteries is expected to continue growing with the increasing prevalence of laptop computers, cellular phones, and other portable electronic devices. Batteries represent a large volume of toxic materials in common use, and there are currently no adequate substitutes for the toxic and hazardous materials used in batteries.The majority of research on battery waste management has been directed towards automobile lead acid batteries, and rechargeable batteries such as those used in portable electronics have been given less attention.

Problem Statement

Our work will investigate the life cycle environmental implications of various types of rechargeable batteries and the alternatives for managing their toxic materials. Currently there is little standardization of recommendations for consumer use, disposal or recycling of batteries. Government regulations concerning waste batteries are varied. By examining actual production, distribution, use, collection, and recycling systems for these batteries, we can better evaluate the implicit and explicit policies for current practices and the related problems.

Proposed Approach

This project will take a systematic view of the current status of pollution prevention in terms of the life cycle use of batteries used in laptop computers, telecommunications devices, and other portable consumer electronics. Analysis of the life cycle will include tracing the materials through the mining and manufacturing processes, the application and use of batteries, and recycling and disposal. These stages of the life cycle can be linked with materials accounting and mass balance methods. Battery manufacturing will be examined by using a materials accounting approach, following the inputs and outputs of key materials. The research will consider alternative possibilities and practices for smelting operations. Topics such as returning batteries to the manufacturer for recycling and disposal will be considered, since a major economic obstacle in battery waste management is the collection of used batteries. Another potential area of pollution prevention is in the use of the electronic equipment itself. Reducing the power needed to operate portable electronics would decrease the total number of batteries needed. Manufacturers should also explore the possibilities for alternative battery designs which could provide power more efficiently; lithium-ion and lithium-polymer batteries have exciting potential in this respect.

Battery Type	Specific Energy (Wh/Kg)	Specific Power (W/kg)
Alkaline	150	14
Lead-acid	35	~200
Lithium-ion 115	400	500
Lithium-polymer	100-200	>200
Nickel-cadmium	40-60	220-360
Nickel-metal hydride 60 475	60	475
Zinc-air	146	150

Application

This study of battery life cycles and analysis of options will provide a framework for considering manufacturing systems, materials selection, and future policy decisions and research concerning battery waste management. A variety of empirical data sources can be used for this study, including environmental reports of toxic materials (RCRA and TRI reports), census data, and industrial case studies.

For more information contact:

Francis McMichael Phone: (412) 268-8365

Email: fm2a@cmu.edu

Financial Support

AT&T Foundation Green Design Initiative at Carnegie Mellon U.

IBM Environmental Research Program

National Science Foundation