Lithium‐ and Manganese‐Rich Oxide Cathode Materials for High‐Energy Lithium Ion Batteries

Abstract

Layered lithium‐ and manganese‐rich oxides (LMROs), described as xLi2MnO3·(1–x)LiMO2 or Li1+yM1–yO2 (M = Mn, Ni, Co, etc., 0 < x <1, 0 < y ≤ 0.33), have attracted much attention as cathode materials for lithium ion batteries in recent years. They exhibit very promising capacities, up to above 300 mA h g−1, due to transition metal redox reactions and unconventional oxygen anion redox reaction. However, they suffer from structural degradation and severe voltage fade (i.e., decreasing energy storage) upon cycling, which are plaguing their practical application. Thus, this review will aim to describe the pristine structure, high‐capacity mechanisms and structure evolutions of LMROs. Also, recent progress associated with understanding and mitigating the voltage decay of LMROs will be discussed. Several approaches to solve this problem, such as adjusting cycling voltage window and chemical composition, optimizing synthesis strategy, controlling morphology, doping, surface modification, constructing core‐shell and layered‐spinel hetero structures, are described in detail.

Investigation of Li1.17Ni0.20Mn0.53Co0.10O2 as an Interesting Li‐ and Mn‐Rich Layered Oxide Cathode Material through Electrochemistry, Microscopy, and In Situ Electrochemical Dilatometry

“…substituted Mn with Al, which was effective in mitigating the capacity fading and discharge voltage decay upon cycling as compared to un‐doped Li 1.2 Ni 0.16 Mn 0.56 Co 0.08 O 2 . More information on approaches which can improve the electrochemical performance of Li and Mn‐rich cathodes can be found in several review articles . It is important to note that although there are several reports on successful mitigation of capacity and voltage fading of HENCM cathodes by doping, it is hard to study and fully understand the effect of doping of these materials due to their initial bi‐phase structure.…”

“…[16,17] The formation of a spinel LiÀ MnÀ O phase leads to the famous voltage fading of these cathodes, namely, the average voltage becomes lower upon cycling,due to a major redox activity of this phase around 3 V. [14,16] [19] More information on approaches which can improve the electrochemical performance of Li and Mn-rich cathodes can be found in several review articles. [6,[20][21][22] It is important to note that although there are several reports on successful mitigation of capacity and voltage fading of HENCM cathodes by doping, [19,23] it is hard to study and fully understand the effect of doping of these materials due to their initial bi-phase structure. Because dopants may concentrate in the interphase regions, in locations where their impact on structure and composition cannot be explored properly.…”

Voltage fade mitigation in the cationic dominant lithium-rich NCM cathode

“…A substantial number of compositions, nearly 800, with layered or spinel structure have been clearly identified 3 . Due to ions migration leads to an unusual atomic restructuring hence most phases are even more complicated after the first cycle [19][20][21][22] .…”

Inkjet Printing of Li‐Rich Cathode Material for Thin‐Film Lithium‐Ion Microbatteries

“…The discharge capacity of Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 (LMR) materials depends on composition (ratio of Li 2 MnO 3 and LiNi 1/3 Co 1/3 Mn 1/3 O 2 ) and voltage range reaching 250 mAh g −1 and higher. They can provide stable performance in a wide range of potentials (2.0–4.8 V) and specific energy can reach 900 mWh g −1 …”