Factors Contributing to Path Hysteresis of Displacement and Conversion Reactions in Li Ion Batteries

We investigate the thermodynamic and kinetic attributes of electrode materials that are necessary to suppress path hysteresis during displacement and conversion reactions in Li ion batteries. We focus on compounds in the Li–Cu–Sb ternary composition space, as the displacement reaction between Li_1+ϵCu_1+δSb and Li₃Sb can be cycled reversibly. A first-principles analysis of migration barriers indicates that Cu, while not as mobile as Li in the discharged phase (Li₃Sb), nevertheless should exhibit mobilities similar to that of Li in common intercalation compounds. A calculation of phase stability in the ternary Li–Cu–Sb system predicts that the intermediate phases along the reversible charge/discharge path are stable in a large Cu chemical potential window. This ensures that intermediate phases are not bypassed upon Li extraction even when large thermodynamic driving forces are needed to reinsert Cu into the discharged electrode. Our study suggests that the suppression of path hysteresis during displacement reactions requires (i) a high mobility of the displaced metal and (ii) the thermodynamic stability of intermediate phases along the reversible path in a wide metal chemical potential window. Even in the absence of path hysteresis, displacement and conversion reactions suffer from polarization needed to set up thermodynamic driving forces for metal extrusion and reinsertion. This polarization can be estimated with a Clausius–Clapeyron analysis

Effect of Tricalcium Aluminate on the Physicochemical Properties, Bioactivity, and Biocompatibility of Partially Stabilized Cements - Figure 5

<p>(A) Cytotoxicity assessment of PSC-91, PSC-73, PSC-55 and mineral trioxide aggregate (MTA) by LDH assay according to ISO-10993 protocol standard. All tested cements on dental pulp cells were evaluated by LDH assay on 1day and 3 days. Each bar illustrated average absorbance (A490 nm) ± SD. No significant differences between PSC-91, PSC-73 and MTA (P>0.05); (B) Cell viability evaluation by WST-1 assay. Each bar illustrated average absorbance (A440 nm) ± SD.</p

The pH value and physical properties of all tested cements.

<p>(A) pH values variation of all tested cements at various time intervals. (B) The initial and final setting times of PSC-91, PSC-73, PSC-55 and MTA. (C) Compressive strength of PSC with different C3S and CSA content and MTA at 4-h, 24-h and 168-h.</p

The evaluation of biomineralization in human dental pulp cells by Alizarin Red S staining.

<p>The evaluation of biomineralization in human dental pulp cells by Alizarin Red S staining.</p

Schematic diagrams of the preparation of PSC.

<p>ASB  =  aluminum s<i>ec</i>-butoxide; CNT  =  calcium nitrate; TOES  =  tetraethyl orthosilicate; PSC  =  partial stabilized cement.</p

SEM micrograph of the surface of specimens stored in simulated body fluid (SBF) various durations.

<p>Soaked in SBF after 1 day: (A) PSC-91 (B) PSC-73 (C) PSC-55 (D) MTA; Soaked in SBF for 7 days: (E) PSC-91 (F) PSC-73 (G) PSC-55 (H) MTA</p

XRD powder patterns of unhydrated cements and hydrated PSCs stored in D.I. water for 1, 3 and 7 day.

<p>(A) the unhydrated of PSC-91, PSC-73, and PSC-55 after calcined at 1400°C for 2 h and unhydrated MTA; (B) the hydrated patterns of PSC-91; (C) the hydrated patterns of PSC-73; (D) the hydrated patterns of PSC-55. [★ C3A; C3S; Bi₂O₃; ▪ Ca(OH)₂; ▴ CSH; • C₃AH₆].</p