Electrochemical and morphological study of the effect of temperature on the restructuring and loss of capacity of alkaline battery electrodes. Final report

Technical Report · Thu Nov 01 04:00:00 EST 1984

OSTI ID:5906484

Macdonald, D D; Pound, B G; Lenhart, S J

The degradation processes occurring within porous nickel battery electrodes were investigated during charge/discharge cycling at temperatures in the range 0 to 100/sup 0/C. The ac impedance of two types of porous nickel electrodes (sintered electrodes and rolled and bonded electrodes) in a 8 m KOH solution was measured, and the data were analyzed in terms of a transmission line model (TLM). In addition, cyclic voltammetry was used to study the characteristics of the oxygen evolution reaction on nickel electrodes during charging. Impedance data of planar, non-porous electrodes were obtained over a range of potentials and temperatures in order to provide an equivalent circuit to model the pore-wall and backing-plate interfacial impedance components in the TLM. Parameters in the TLM were curve-fitted to experimental impedance data obtained for porous electrodes at different stages of cycling. Changes in these parameters with cycling time for rolled and bonded electrodes were consistent with experimental observations, and could be attributed to various degradation processes. The principal changes found to occur with increasing cycle number were that the average pore effective length decreases and the average solid-phase resistivity increases. The impedance data for sintered electrodes do not change during galvanostatic cycling and failures occur abruptly after a relatively large number of cycles. Consequently, the TLM provides little insight into cycle-dependent degradation phenomena on sintered electrodes.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5906484
• Report Number(s): LBL-18716; ON: DE85006869
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
250902* -- Energy Storage-- Batteries-- Performance & Testing
CAPACITY
CHARGE EXCHANGE
CHEMISTRY
ELECTRIC BATTERIES
ELECTRIC IMPEDANCE
ELECTROCHEMICAL CELLS
ELECTROCHEMISTRY
ELECTRODES
ELEMENTS
IMPEDANCE
MATERIALS
METALS
MORPHOLOGICAL CHANGES
NICKEL
POROUS MATERIALS
TEMPERATURE EFFECTS
TRANSITION ELEMENTS
VOLTAMETRY