Multifunctional Surface Construction for Long‐Term Cycling Stability of Li‐Rich Mn‐Based Layered Oxide Cathode for Li‐Ion Batteries

Abstract

Li‐rich Mn‐based layered oxides (LMLOs) are promising cathode material candidate for the next‐generation Li‐ion batteries (LIBs) of high energy density. However, the fast capacity fading and voltage decay as well as low Coulombic efficiency caused by irreversible oxygen release and phase transition during the electrochemical process hinder their practical application. To solve these problems, in the present study, a multifunctional surface construction involving a coating layer, spinel‐layered heterostructure, and rich‐in oxygen vacancies is successfully conducted by a facile thermal reduction of the LMLO particles with potassium borohydride (KBH4) as the reducing agent. The multifunctional surface structure plays synergistic effects on suppressing the interface side reaction, reducing the dissolution of transition metal, increasing electron conductivity and lithium diffusion rate. As a result, electrochemical performances of the LMLO cathode are effectively enhanced. With optimization of the addition of KBH4, the electrode delivers a reversible capacity of 280 mAh g−1 at 0.1 C, which maintains after 100 cycles. The capacity retention with respect to the initial capacity is as high as 98% at 1 C after 400 cycles. The present work provides insights into designing a highly effective functional surface structure of LMLO cathode materials for high‐performance LIBs.

Construction of LiNi0.5Mn1.5O4 Spinel Layer-Bearing Heterostructural Li-Rich Layered Oxide Cathodes with Enhanced Structural Integrity and Cycling Stability

“…All samples are indexed with a hexagonal α-NaFeO 2 structure belonging to the space group of R -3 m . The weak diffraction peaks located at 20–25° are assigned to the superlattice honeycomb ordering of the monoclinic Li 2 MnO 3 phase . No diffraction peaks belonging to other impurity phases are identified.…”

“…The increase in Δ E illustrates an increased content of Mn 3+ . The Mn valence can be calculated using the follow equation: v Mn = 9.67 − 1.27 × normalΔ E 3 s / eV …”

Efficient Palladium Catalysts: Application and Challenges of Electrocatalytic Hydrodechlorination Technology in Wastewater Treatment

“…As the technology for modulating metal dispersion became more sophisticated, single‐atom catalysts had been developed in the field of electrocatalysis [31] . The single‐atom Pd catalyst facilitated the Volmer reaction and produced more H* favorable for dechlorination [32] In single‐atom catalysts, the metal catalysts were not aggregated because the individual metals were anchored by heteroatoms [33] . The metal single‐atom catalysts prepared in this way were able to achieve 100 % utilization [34] .…”

Review on comprehending and enhancing the initial coulombic efficiency of Li-rich Mn-based cathode materials in lithium-ion batteries

“…31 Yan et al reported that a multifunctional surface construction involving a coating layer, spinel-layered heterostructure, and rich-in oxygen vacancies was successfully conducted through facile thermal reduction of the LMO particles with potassium borohydride as the reducing agent. 32 The surface/interface 33 of LMOs has been achieved by the reconstruction of a surface structure, for example, Wu et al put forward a feasible interfacial modification strategy in virtue of Mn 3 O 4 surface coating to construct a protective shell at the surface of LMOs. 34 The modified material exhibits a high ICE of 84.3% and the capacity retention is 95.6% at 1C after 200 cycles.…”