Battery resistance and its effects on performance of laminate film type Co-PBA/Ni-PBA tertiary battery

Abstract

Abstract Tertiary battery (TB) can be charged by heating or cooling via difference in the electrochemical Seebeck coefficient α between cathode and anode. Here, we investigated battery resistance R and its effect on thermal cycle properties in laminate film type Na{1.48Co[Fe(CN)6]{0.87 (Co-PBA) / Na{1.76Ni[Fe(CN)6]{0.94} (Ni-PBA) TB. We found that charge-transfer resistance Rct and diffusion resistance Rdif are the dominant components of $R$ while solution resistance Rs has minor role. Regardless of the solute type, R varied inversely proportional to the Na+ concentration M. In high-R TB, the thermal voltage VTB and discharge capacity QTB per unit weight of the total active material is significantly suppressed, which is quantitatively explained in terms of the voltage drop (= IR; I is current) during the discharge process.