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Title: Development of novel strategies for enhancing the cycle life of lithium solid polymer electrolyte batteries. Final report

Lithium/solid polymer electrolyte (Li/SPE) secondary batteries are under intense development as power sources for portable electronic devices as well as electric vehicles. These batteries offer high specific energy, high energy density, very low self-discharge rates, and flexibility in packaging; however, problems have inhibited their introduction into the marketplace. This report summarizes findings to examine processes that occur with Li/SPE secondary batteries upon cyclic charging/discharging. The report includes a detailed analysis of the impedance measured on the Li/SPE/IC and IC/SPE/IC systems. The SPE was a derivative of methoxyethoxyethoxyphosphazene (MEEP) with lithium triflate salt as the electrolyte, while the intercalated cathodes (IC) comprised mixtures of manganese dioxide, carbon powder, and MEEP as a binder. Studies on symmetrical Li/SPE/Li laminates show that cycling results in a significant expansion of the structure over the first few tens of cycles; however, no corresponding increase in the impedance was noted. The cycle life of the intercalation cathode was found to be very sensitive to the method of fabrication. Results indicate that the cycle life is due to the failure of the IC, not to the failure of the lithium/SPE interface. A pattern recognition neural network was developed to predict the cycle life of a battery frommore » the charge/discharge characteristics.« less
Authors:
; ; ; ; ; ;
Publication Date:
OSTI Identifier:
810692
Report Number(s):
DOE/ER/14387--1
TRN: US200716%%537
DOE Contract Number:
FG02-93ER14387
Resource Type:
Technical Report
Research Org:
The Pennsylvania State University, University Park, PA (US)
Sponsoring Org:
Division of Chemical Sciences, Office of Basic Energy Sciences, USDOE Office of Energy Research (ER)
Country of Publication:
United States
Language:
English
Subject:
25 ENERGY STORAGE; CARBON; CATHODES; ELECTRIC BATTERIES; ELECTROLYTES; ENERGY DENSITY; FABRICATION; FLEXIBILITY; IMPEDANCE; LITHIUM; MANGANESE; METAL-NONMETAL BATTERIES; MIXTURES; NEURAL NETWORKS; PATTERN RECOGNITION; POLYMERS; SERVICE LIFE; SOLAR PROTONS; SOLID ELECTROLYTES METAL-NONMETAL BATTERIES; LITHIUM; CLATHRATES; SOLID ELECTROLYTES; POLYMERS; IMPEDANCE; SERVICE LIFE; FAILURES; CATHODES; PROGRESS REPORT AROMATICS; FORECASTING