Lithium Trapping in Microbatteries Based on Lithium‐ and Cu₂O‐Coated Copper Nanorods

Abstract

Microbatteries based on three‐dimensional (3D) electrodes composed of thin films of Li and Cu2O coated on Cu nanorod current collectors by electrodeposition and spontaneous oxidation, respectively, are described and characterised electrochemically. High‐resolution scanning electron microscopy (HR‐SEM) data indicate that the Li electrodeposition resulted in a homogenous coverage of the Cu nanorods and elemental analyses were also used to determine the amount of lithium in the Li‐coated electrodes. The results show that 3D Cu2O/Cu electrodes can be cycled versus 3D Li/Cu electrodes but that the capacity decreased during the cycling due to Li trapping in the Cu current collector of the 3D Li/Cu electrode. These findings highlight the problem of using copper current collectors together with metallic lithium as the formation of a solid solution yields considerable losses of electroactive lithium and hence capacity.

Lightweight, Thin, and Flexible Silver Nanopaper Electrodes for High‐Capacity Dendrite‐Free Sodium Metal Anodes

“…In Figure c, it can be seen that the Al foil electrode exhibited an initial CE value of 90%, which gradually increased to 100% after 15 cycles, after which significant fluctuations in CE were observed. Such effects are commonly ascribed to interface instabilities at the electrode surface, Na trapping problems, and uncontrolled SEI formation . Compared to the Al foil electrode, the AgNP electrode demonstrated a higher initial CE of 93.9%, which increased to 100% on the 2nd cycle and then remained fairly stable.…”

Effects of Electrolyte Additives and Nanowire Diameter on the Electrochemical Performance of Lithium‐Ion Battery Anodes based on Interconnected Nickel–Tin Nanowire Networks

“…In the absence of nanowire pulverization, the capacity fade has been ascribed to the two processes in nanostructured electrodes-excessive SEI growth [18,36,37] and lithium trapping. [30,[38][39][40][41][42][43][44] The schematics of these processes are shown in Figure 4 for nanowire electrodes.…”

“…On the other hand, lithium trapping (Figure 4b) occurs as a result of incomplete delithiation of nanoparticle electrodes. [30,[38][39][40][41][42][43][44] During the first lithiation, the lower cutoff potential tends to be reached before complete electrode alloying (this unreacted or inaccessible zone has been denoted as "IZ" in Figure 4b). During the subsequent delithiation, lithium concentration gradients then exist in two directions-toward both the electrode surface and the IZ-giving rise to "two-way lithium diffusion."…”

“…[30] Recent studies indicate that these observations in nanowire Li-alloying anodes can be ascribed to both instable SEI growth [18,36,37] and lithium trapping. [30,[38][39][40][41][42][43] The large specific surface areas of nanowire electrodes and the volume change they undergo during (de)lithiation result in an instable SEI that continually grows with each cycle, leading to low CE, increased polarization, and electrode failure. Li trapping occurs due to incomplete delithiation of Li-alloying nanoparticle electrodes, [30,[38][39][40][41][42][43][44] which causes a gradual buildup (%1% of the lithiation charge on each cycle) of Li in the material, reducing the charge that can be deposited on subsequent cycles.…”

Lithium permeation within lithium niobate multilayers with ultrathin chromium, silicon and carbon spacer layers

“…The capacity loss seen upon cycling lithium ion batteries (LIBs) was recently attributed to diffusive loss of Li in current collectors. 83,84 Li that has reached the current collector (or the Cr layer) is no more in an ionic state. In that case, the Li permeation happens only by Li diffusion without an electrical driving force.…”