Spinel LiNixMn2−xO4 as cathode material for aqueous rechargeable lithium batteries

Abstract

Ni-doped spinel LiNixMn2-xO4 (x = 0, 0.05, 0.10) samples were prepared by a sol-gel method. Structure and morphology of the samples were characterized by X-ray diffraction, scanning electron microscopy, BrunnauerEmmet-Teller method and inductively coupled plasma atomic absorption spectrometry. The electrochemical behavior as a cathode material (positive mass) for aqueous rechargeable lithium batteries (ARLBs) was investigated by cyclic voltammetry, electrochemical impedance spectroscopy, capacity measurements and cycling tests. The results show that the LiNi 0.1Mn1.9O4 electrode presents the best rate and cycling performance but low reversible capacity. In contrast, the LiNi 0.05Mn1.95O4 electrode shows a higher reversible capacity and relatively good cycling behavior. At a current density of 150 mA g-1, LiNi0.05Mn1.95O4 delivers a reversible capacity of 102 mA h g-1. At the relative high current densities of 1500 and 3000 mA g-1, the LiNi 0.05Mn1.95O4 electrode still delivers reversible capacities of 95.0 and 88.7 mA h g-1, respectively. The Ni-doped samples show excellent cycling life in 0.5 mol L-1 Li 2SO4 aqueous solution. The capacity retention ratios for LiNi0.05Mn1.95O4 and LiNi0.10Mn 1.90O4 after 800 cycles at a current density of 1500 mA g-1 are 79.4% and 91.1%, respectively, much higher than that for the undoped LiMn2O4 at only 37.8%. 2013 Elsevier Ltd. 2013 Elsevier Ltd. All rights reserved.

Facile synthesis and electrochemical performances of secondary carbon-coated LiFePO4-C composite for Li-ion capacitors based on neutral aqueous electrolytes

“…In addition, the high-rate performance can be achieved due to the high ionic conductivity of aqueous electrolytes [2]. For now, a few Li-ion materials were reported as the cathode materials of LIBs in the aqueous electrolytes such as LiMn 2 O 4 [10,11], LiNi x Mn 2-x O 4 [12] and LiFePO 4 (LFP) [13]. Olivinetype LFP which was reported by Goodenough in 1997 has been widely used as the cathode material for LIBs because of its low toxicity, low cost, high capacity (170 mAh g -1 ), high discharge potential (*3.4 V vs. Li ?…”

Controlling the Lithium Intercalation Voltage in the Li(Mn1-x Ni x )2O4 Spinel Via Tuning of the Ni Concentration: A Density Functional Theory Study.

“…Substitutional doping of LMO is an option to avoid the JT-active 3+ oxidation state in the six-fold Mn cations. Replacing the appropriate proportion of this cation by transition metal atoms 5 with a preferred stable oxidation state below 3+ has proven so far to be the best strategy to ensure that manganese is exclusively in the Mn 4+ form in LMO. For example, 25 % 6 doping by the highly stable Ni 2+ , with the e g state half filled, promotes the oxidation of all Mn ions to the JT-inactive 4+ oxidation state.…”

Significant Improvement of LiMn₂O₄ Cathode Capacity by Introducing Trace Ni During Rapid Microwave-induced Solution Combustion

“…[17][18][19] Additionally, the shorter chemical bond between the doped cations and oxygen than the Mn-O bond improves the structure stability of LiMn 2 O 4 . 20,21 The reasons for improved cycle performance by Ni element are summarized as follows: (1) higher electronegativity of Ni element (1.8) than that of Mn (1.5), (2) shorter bond length of the Ni-O bond (1.9154 ¡) than that of the Mn-O bond (1.9372 ¡), resulting in improving structure stability, 22 and (3) the transformation of from ferromagnetic Mn 3+ -O 2¹ -Mn 4+ into diamagnetic Mn 4+ -O 2¹ -Mn 4+ by replacing part of Mn 3+ , further improving the structure stability. 23 Duan et al 24 synthesized nickel-doped LiNi x Mn 2¹x O 4 (0¯x0 .1) cathode material using a solution combustion synthesis technology.…”