3D Porous Cu–Zn Alloys as Alternative Anode Materials for Li‐Ion Batteries with Superior Low T Performance

Abstract

Zinc is recently gaining interest in the battery community as potential alternative anode material, because of its large natural abundance and potentially larger volumetric density than graphite. Nevertheless, pure Zn anodes have shown so far very poor cycling performance. Here, the electrochemical performance of Zn‐rich porous Cu–Zn alloys electrodeposited by an environmentally friendly (aqueous) dynamic hydrogen bubble template method is reported. The lithiation/delithiation mechanism is studied in detail by both in situ and ex situ X‐ray diffraction, indicating the reversible displacement of Zn from the Cu–Zn alloy upon reaction with Li. The influence of the alloy composition on the performance of carbon‐ and binder‐free electrodes is also investigated. The optimal Cu:Zn atomic ratio is found to be 18:82, which provides impressive rate capability up to 10 A g−1 (≈30C), and promising capacity retention upon more than 500 cycles. The high electronic conductivity provided by Cu, and the porous electrode morphology also enable superior lithium storage capability at low temperature. Cu18Zn82 can indeed steadily deliver ≈200 mAh g−1 at −20 °C, whereas an analogous commercial graphite electrode rapidly fades to only 12 mAh g−1.

Synthesis Process of CoSeO3 Microspheres for Unordinary Li‐ion Storage Performances and Mechanism of Their Conversion Reaction with Li ions

“…In the consecutive discharge process, no reflection assignable to either Li 2 O or Li 2 Se could be detected, which consequently suggested their presence in the form of amorphous phases. [44] Peaks recorded at 42.2° and 29.9° during the subsequent charge process corresponded to the (−111) crystal plane of the CoO phase and the (211) crystal plane of the SeO 2 phase, respectively, as shown in Figure 5d,e. Therefore, the CV curves and in situ XRD patterns effectively supported the mechanism of the conversion reaction of CoSeO 3 with Li ions.…”

“…In the initial discharge process, CoSeO 3 was reduced to metallic Co and Se and the Li 2 O phase, which corresponded to one clear discharge plateau at around 1.3 V. This conversion reaction was reflected in the disappearance of the main peaks of CoSeO 3 at 30.9° and 31.7° corresponding to the (−423) and (223) crystal planes, respectively, as shown in Figure c. In the consecutive discharge process, no reflection assignable to either Li 2 O or Li 2 Se could be detected, which consequently suggested their presence in the form of amorphous phases . Peaks recorded at 42.2° and 29.9° during the subsequent charge process corresponded to the (−111) crystal plane of the CoO phase and the (211) crystal plane of the SeO 2 phase, respectively, as shown in Figure d,e.…”

“…To elucidate the lithiation and delithiation processes of CoSeO 3 , in situ XRD analysis was performed during the first cycle at a current density of 0.1 A g −1 in the potential range of 0.001–3.0 V. The XRD patterns and voltage profiles recorded at regular intervals during the initial discharge and charge processes are shown in Figure b. The obviously sharp peaks at 45.8°, 50.9°, 52.8°, and 70.9° were attributed to Be . Be sheet was utilized as the anode electrode, which was coated with CoSeO 3 active material.…”

“…The obviously sharp peaks at 45.8°, 50.9°, 52.8°, and 70.9° were attributed to Be. [44] Be sheet was utilized as the anode electrode, which was coated with CoSeO 3 active material. Three magnified regions depicting the phase transformation of CoSeO 3 during the first cycle are shown in Figure 5c-e.…”

3D zinc@carbon fiber composite framework anode for aqueous Zn–MnO2 batteries

“…Primary Zn dendrites can puncture the diaphragm, causing short circuits. Lots of approaches have been proposed to optimize these problems such as adding additives in the electrolyte to modify the deposition behavior, 21,22 coating a new protective layer on the surface of Zn metal 23,24 or using Zn-alloy [25][26][27] to improve conductivity and anti-corrosion property. Unfortunately, most of the improvements are either expensive or hard to maintain a long lifespan during cell cycling.…”