A methodology for analyzing aging and performance of lithium-ion batteries: Consistent cycling application

Systems and Methods for Transformation and Degradation Analyses

“…Observed behaviors accord with theoretical anticipations presented previously. Similar results were obtained and published for seven lithium-ion batteries [17,19,30], four heavy-duty leadacid batteries [19,23], a nickel-metalhydride battery, a supercapacitor and a fuel cell [18]. See section 9.2 for thermal runaway characterization Table 4.…”

“…Hence, the energy available for work (represented by the blue line in Figure 3(b)) depends on the fraction of the theoretical total (the green line) lost to microstructural transformations and entropy generation. As anticipated by formulations in reference [26,30] and Section 4.2, high entropic efficiency 𝜂 𝑆′ is always preferred for slow degradation and optimum performance. in the reversible transformation subspace.…”

“…The dissipation factor [18,26,30] which measures a non-thermal system's dissipation tendencies relative to useful work output/chemical reaction is…”

“…Reversible current 𝐼 𝑟𝑒𝑣 can be obtained as the initial current in a constant-resistive load discharge step, when the battery is at its healthiest. This allowed the convenient choice of the widely used capacity fade as degradation measure [17,23,30].…”

“…This is in addition to each recharge step being an energy-addition step without which the battery would remain in a degraded state. Figure 2, from data presented in [30], shows the cyclic capacity fade-the difference between the initial/reference total charge content in the battery and the present total charge content-measured on a Samsung single-cell 3.6 V, 2.5 Ah lithium-ion polymer battery. Figure 2(a) shows that after the first 6 discharge steps, discharge capacity dropped by 0.06 Ah, then the 9 th and 10 th cycles recovered this loss.…”