Practical Prelithiation of 4.5 V LiCoO₂||Graphite Batteries by a Passivated Lithium‐Carbon Composite

Abstract

Prelithiation can replenish active Li into the battery to compensate the Li consumption due to the formation of solid electrolyte interphase (SEI) on the electrode surface, therefore improving the energy density of Li‐ion batteries (LIBs), especially for batteries using electrode materials with low initial Coulombic efficiency (ICE). However, practical prelithiation in LIBs is a challenge since most lithiated compounds with high specific capacity are unstable and industrially incompatible. Herein, an effective prelithiation strategy is demonstrated by using a lithium‐carbon (Li‐C) microsphere composite. These Li‐C microspheres are passivated by a self‐assembled monolayer of octadecylphosphonic acid, which suppresses the reaction between Li and commonly used slurry solvent 1‐methyl‐2‐pyrrolidinone (NMP). After the addition of passivated Li‐C into the NMP‐based graphite slurry, the ICE of the graphite||Li half‐cell boosts from 88.5% to 100.5%. In a 4.5 V LiCoO2(LCO)||graphite full‐cell, the supplementary Li source avoids excessive delithiation of LCO, thus suppressing the destructive phase transformation at high delithiation potential. As a result, the prelithiated LCO||graphite full‐cell presents an initial discharge capacity of 201 mAh g−1 and the capacity retention after 100 cycles increases by 7.1 %. This work provides a practical approach for developing high energy density and long cycle life LIBs.

Hydrogen-Treated Spent Lithium Cobalt Oxide as an Efficient Electrocatalyst for Oxygen Evolution

“…As for the XPS spectrum of Li 1s (Figure 4b), it can be seen that only the peak of Li + at 54.5 eV is observed. 32 After hydrogen treatment, the peak of Li + is enhanced because Li 0.5 CoO 2 is reduced to LiCoO 2 , which is in good agreement with the XRD result.…”

“…It can be seen from the full XPS spectrum (Figure a) that the samples contain three elements of Li, Co, and O, which are consistent with the results of ICP (Table S1). As for the XPS spectrum of Li 1s (Figure b), it can be seen that only the peak of Li + at 54.5 eV is observed . After hydrogen treatment, the peak of Li + is enhanced because Li 0.5 CoO 2 is reduced to LiCoO 2 , which is in good agreement with the XRD result.…”

Amide‐Functional, Li3N/LiF‐Rich Heterostructured Electrode Electrolyte Interphases for 4.6 V Li||LiCoO2 Batteries

“…Contrarily, the irreversible phase transition with blank electrolyte results in capacity decay and structure destruction, leading to aggravated surface‐side reaction. [ 37 ] Compared with 2‐TPIC, the CEI with 4‐TPIC is better than that with 2‐TPIC in inhibiting the dissolution of Co ions due to the presence of more amide groups (Figure S6, Supporting Information). The atomic ratio in the CEI of LiCoO 2 cathode with different electrolytes was summarized in Figure S7, Supporting Information.…”

Porosification and Fe3+ Intercalation of Spent LiCoO2 as an Efficient Oxygen Evolution Electrocatalyst

“…It can be seen that there is a peak at the binding energy of 54.5 eV, which belongs to Li + . 39 After the intercalation of Fe 3+ , there is an additional peak that appears at 56.5 eV corresponding to Fe 3p. 40,41 It is found by fitting that there is only Fe (III), which suggests that Fe is not oxidized or reduced during the intercalation process.…”