Enhanced cycling stability and rate capability of Bi₂O₃-coated Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ cathode materials for lithium-ion batteries

Abstract

The LMNC-BO electrode presents an enhanced cycle performance, better rate capability and structural stability than bare LMNC.

The Influences of Surface Coating Layers on the Properties of Layered/Spinel Heterostructured Li-Rich Cathode Material

“…In addition, there is an internal resistance of the cell (R s ) in the high-frequency area. 7 As seen from Figure 7f and Table 3, the values of R f and R ct for LS@LP are 26.8 and 20.2 Ω, respectively, which are much less than the respective values of LS@LF (58.2 and 24.5 Ω), LS@LT (64.3 and 28 Ω), and LS (92.3 and 49.06 Ω). The samples after coating had a smaller R f+ct value, which suggests that the coating layers can suppress the interface side reactions between the cathode and electrolyte and reduce the interfacial resistance.…”

“…As seen, there are two semicircles and one slope, which are consistent with previous research. ,, The semicircle in the high-frequency region responds to the transportation of Li + through the solid–electrolyte interface ( R f ), and the semicircle in the middle-frequency region is related to the charge-transfer reaction ( R ct ) at the surface of the electrode. In addition, there is an internal resistance of the cell ( R s ) in the high-frequency area . As seen from Figure f and Table , the values of R f and R ct for LS@LP are 26.8 and 20.2 Ω, respectively, which are much less than the respective values of LS@LF (58.2 and 24.5 Ω), LS@LT (64.3 and 28 Ω), and LS (92.3 and 49.06 Ω).…”

“…Of late, Li-rich layered oxide cathode materials, which have a composition of x Li 2 MnO 3 ·(1 – x )­Li M O 2 ( M = Mn, Ni, Co, etc. ), have received enormous amounts of attention in virtue of their reversible capacities over 250 mAh g –1 , operating voltages higher than 4.6 V vs Li/Li + , and low cost. , However, there are several challenges that demand to be overcome before large-scale commercial application can take place, e.g., large initial irreversible capacity loss on account of the removal of Li 2 O from the Li 2 MnO 3 phase, along with the generation of oxygen ion vacancies in the initial charging and poor rate capability . Especially in the case of delithiation, cathode materials can react easily with organic electrolyte, which can lead to the dissolution of transition metals and further cause phase transformation, capacity fading, and voltage decay. − In recent years, the spinel structure with three-dimensional Li-ion diffusion channels has received great attention because it can greatly raise the diffusion rate of Li-ions and reduce the initial irreversible capacity loss. , Further, there are many reports regarding the preparation of integrating the spinel phase and a layered Li-rich phase; for example, Wang et al.…”

“…5,6 However, there are several challenges that demand to be overcome before large-scale commercial application can take place, e.g., large initial irreversible capacity loss on account of the removal of Li 2 O from the Li 2 MnO 3 phase, along with the generation of oxygen ion vacancies in the initial charging and poor rate capability. 7 Especially in the case of delithiation, cathode materials can react easily with organic electrolyte, which can lead to the dissolution of transition metals and further cause phase transformation, capacity fading, and voltage decay. 8−10 In recent years, the spinel structure with three-dimensional Li-ion diffusion channels has received great attention because it can greatly raise the diffusion rate of Liions and reduce the initial irreversible capacity loss.…”

Fluorine-Doped Carbon Surface Modification of Li-Rich Layered Oxide Composite Cathodes for High Performance Lithium-Ion Batteries

“…Furthermore, compared to that of most reported Li-rich layered oxide cathodes, the LMCNO@C-F fabricated in this work shows an excellent electrochemical performance (see Table S5). − Especially, the rate performance and cycling performance of the LMCNO@C-F are better than the above-reported LMNCO materials. The results suggest that F-doped carbon surface modified LMNCO is a promising cathode materials for fabrication of high performance LIBs.…”