Understanding the Feasibility of Manganese Substitution for Cobalt in the Synthesis of Nickel-Rich and Cobalt-Free Cathode Materials

Abstract

LiNi 0.8 Co 0.15 Al 0.05 O 2 (LNCA) cathode materials have an extremely high energy density, which can greatly enhance the driving range of pure electric vehicles if they are used in onboard batteries. However, the development of the LNCA cathode material is restricted by the expensive transition metal cobalt (Co). Therefore, researchers are devoted to finding other metals to replace Co to synthesize nickel (Ni)-rich Co-free materials to reduce the cost. To investigate the feasibility of replacing Co with manganese (Mn) as a transition metal, this paper reports the synthesis and compares the properties of four Ni-rich materials with different Co−Mn contents by gradually adding Mn to LNCA materials and reducing the Co content in equal amounts using an oxalic acid coprecipitation method. The results show that Mn can compensate the effect of Co deficiency to a certain extent; it is feasible to use Mn to completely replace Co in the synthesis of Nirich ternary Co-free materials under the premise of sacrificing a certain initial specific capacity. The tetrameric material LiNi 0.8 Co 0.1 Mn 0.05 Al 0.05 O 2 substituted with trace amounts of Mn exhibited the most excellent electrochemical properties among the four synthesized materials. Therefore, to synthesize satisfactory Ni-rich Co-free materials, it is suggested to develop and synthesize quaternary Co-free materials on the basis of LiNi 0.

Mixed solvent-assisted synthesis of high mass loading amorphous NiCo-MOF as a promising electrode material for supercapacitors

“…5l, which were obtained according to the GCD curves of NiCo-MOF-2//AC. Impressively, the NiCo-MOF-2-based SSSC achieved a maximum energy density of 0.65 mW h cm −2 at a power density of 2 mW cm −2 , which is superior to other reported devices, such as NC LDH NSs@Ag@ CC//AC (40 μW h cm −2 at 12.1 mW cm −2 ), 64 Co(OH) 2 /CoOOH/Co 3 O 4 /Cu(OH) 2 //AC (196.1 μW h cm −2 at 1.6 mW cm −2 ), 65 Co 3 O 4 @NiMoO 4 //AC(0.17 mW h cm −2 at 16 mW cm −2 ), 66 Co-MOF/NF//AC (210 μW h cm −2 at 3761.2 μW cm −2 ), 67 NiCo-LDH//AC (31.1 μW h cm −2 at 3.5 mW cm −2 ), 68 Ni 1 Co 2 Al-LDHs@CC//AC (0.102 mW h cm −2 at 0.75 mW cm −2 ), 69 NiO/Ni(OH) 2 /PEDOT//CW/CMK (0.01 mW h cm −2 at 0.33 mW cm −2 ), 70 as well as close to the Co-MOF@NiCo-LDH//AC (0.89 mW h cm −2 at 7.5 mW cm −2 ), 71 and NiCo-NH 2 -BDC-MOF NS/NF//AC (0.81 mW h cm −2 at 1.6 mW cm −2 ) 72 based devices.…”

Insight into the Role of Co and Mn Elements in Ni-Rich LiNi0.9CoxMn0.08–xAl0.02O2 Cathode Materials

“…After reacting for 40 h, the feed was stopped and aged for 30 min. Finally, after filtration, washing, and drying, Ni-rich quaternary precursors with different Co and Mn contents were obtained …”

High Nickel and No Cobalt─The Pursuit of Next-Generation Layered Oxide Cathodes

“…Hence, they will largely inhibit Li/Ni disorder and enhance the reversible lithium de/intercalation, thereby improving the original electrochemical performance. 60 However, Li et al recently reported that the efficacy of Co in high-Ni layered oxides is not good as other dopants (such as Mg, Mn, and Al). 61 Similar amounts of Ni 2+ disorder can be obtained when the LNO is substituted with 5% Mg, Al, and Co, implying that Co cannot achieve an extra reduction of cation mixing.…”

“…According to the previously mentioned magnetic frustration theory, Co 3+ ions do not have a magnetic moment and can help relieve the magnetic frustration in the transition metal layer. Hence, they will largely inhibit Li/Ni disorder and enhance the reversible lithium de/intercalation, thereby improving the original electrochemical performance …”