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Affiliation of Author(s):[1]Univ Elect Sci & Technol China, Sch Mat & Energy, Chengdu 611731, Sichuan, Peoples R China;[2]Univ Elect Sci & Technol China, Yangtze Delta Reg Inst HuZhou, Huzhou 313001, Zhejiang, Peoples R China

Journal:JOURNAL OF COLLOID AND INTERFACE SCIENCE

Key Words:Reduced graphene oxide; Lithium oxide; Hard carbon; Cathode pre-lithiation; Lithium-ion battery

Abstract:Lithium oxides (Li 2 O) possess a considerable theoretical capacity, rendering them highly promising as cathodic pre-lithiation additives. However, its decomposition voltage exceeds the charging cut-off voltage of most cathode materials, hindering its direct use as a cathode sacrificial additive. Herein, we design a facile and safe method to reduce the decomposition energy of Li 2 O at room temperature to offset the irreversible capacity loss by using a core -shell structured Li 2 O-reduced graphene oxide (rGO)-polyethylene glycol (PEG) composite (denoted as Li 2 O- rGO-PEG). The graphene oxide (GO) was heat -treated to remove oxygen functional groups to synthesize rGO, and then reacted with Li 2 O to form a Li 2 O-rGO composite. According to the DFT calculations, the density of states at the Fermi level of Li 2 O-rGO becomes continuous and features a metallic nature, which significantly improves the electrical conductivity of Li 2 O and facilitates electron conduction that modify the delithiation potential of Li 2 O. PEG was used to enhance the cohesive force between rGO and Li 2 O and to protect Li 2 O from atmospheric contamination. Moreover, in order to demonstrate the excellent pre-lithiation ability of Li 2 O-rGO-PEG composite, hard carbon (HC) with low initial coulombic efficiency (ICE) was used as the anode. In the application of LFP (Li 2 O)/HC full cell, Li 2 O was decomposed to Li + to effectively improve the initial charge capacity from 149.7 to 200 mAh/g and discharge capacity from 104.2 to 147.5 mAh/g, which are 33.6 % and 41.6 % higher than those of the pristine LFP/HC full cell, respectively. The cathode pre-lithiation method proposed in this work is simple and environmentally friendly. The successful utilization of Li 2 O as a pre-lithiation additive effectively addressed the issue of low initial coulombic efficiency of the HC, indicating excellent prospects for practical applications.

Document Type:Article

Volume:667

Page Number:688-699

ISSN No.:0021-9797

Translation or Not:no

Release time:2025-05-23