An Alternative Lithium Cathode Material: Synthesis, Characterization, and Electrochemical Analysis of Li8 ( Ni5Co2Mn )  O 16

Abstract

Due to the increased production and use of portable devices, batteries with extended lives and higher power output are in demand. 1 Rechargeable lithium batteries have been extensively investigated as alternatives to standard batteries due to their improved performance characteristics (i.e., cycle life) and environmental friendliness. Each of the components (cathode, anode, and electrolyte) of these rechargeable lithium-ion or "rocking chair" batteries has been extensively investigated. A significant amount of this research has focused on the synthesis, 2-19 processing, 20-28 and/or electrochemical identification 23-25,29-37 of potential cathode (positive electrode) materials for use in these batteries. [38][39][40] Currently, several oxides are being considered for use as 4 V cathode materials for Li batteries: the spinel LiMn 2 O 4 and the layered oxide LiMO 2 (M ϭ Co and/or Ni). 1,41-49 Each of these cathode materials have advantageous and detrimental characteristics that have an impact on their further development for lithium-ion batteries.Recently a unique combination of the standard cathode cations (Co, Mn, Ni) was reported to have some promising features for use as a new cathode material. 50,51 The introduction of Ni ϩ2 to replace Co ϩ2 cations is often used to reduce the cost of the final material while maintaining high capacity. The Mn ϩ3 addition will allow for more flexibility in the charge distribution, as well as further reduce the amount (cost) of Co cations present. Mn is also considered to be a benign material and therefore will be environmentally less damaging than the other cations.We have developed a novel nonaqueous route to standard cathode materials. [38][39][40] Due to the flexibility of this synthetic process, a wide range of cations were found to be easily and homogeneously incorporated into the precursor solution. Previously, we have reported the synthesis of LiMn 2 O 4 with capacity of ϳ80 mAh/g 38,40 and LiCoO 2 with a reversible capacity of ϳ133 mAh/g. 39 In this paper, we report on the synthesis and characterization of the four-cation oxide Li 8 (Ni 5 Co 2 Mn 1 )O 16 , synthesized using a modification of the existing solution-route process. The electrochemical properties and behavior of this material have been investigated and compared with existing cathode materials. ExperimentalThe synthetic method employed was a slight modification of the previously reported synthesis of LiMn 2 O 4 and LiCoO 2 . Full details of the synthesis and characterization of the precursor solutions and materials can be found elsewhere 38-40 and a brief description follows. All manipulations were handled under an argon atmosphere with each precursor being used as received (Aldrich): lithium nitrate (LiNO 3 ), nickel nitrate [Ni(NO 3 ) 2 ], cobalt nitrate [Co(NO 3 ) 2 ], manganese nitrate hexahydrate [Mn(NO 3 ) 2 и6H 2 O), oxalic acid (H 2 C 2 O 4 ) and tetramethyl ammonium hydroxide hydrate (Me 4 NOH). Methanol (MeOH) and tetrahydrofuran (THF) were dried by standard methods immediately prior to use. Mn(NO 3 ...

All-Ceramic Thin Film Battery

“…[2][3][4][5][31][32][33][34][35][36] Each of these cathode materials has advantages and disadvantages that impact their further development for lithium-ion batteries. [1][2][3][4][5]31,33,[36][37][38][39][40][41][42][43][44][45][46] For example, the capacity of the Mn material is low in comparison to the layered oxide materials, and in the case of the Ni-based oxides the synthesis of high-quality materials is problematic. For these and other reasons, LiCoO 2 is often the material of choice for use as the cathode in Li-ion batteries.…”

“…The electrochemical properties of these films were investigated using previously reported methods. 45 The cyclic voltammagrams are shown in Figure 11. Some of the unusual properties were studied in more depth.…”

25 Conducting solids, covering ionic and electronic conductors

“…Boyle et al report the synthesis of Li 8 (Ni 5 Co 2 MnO) 16 as an alternative lithium cathode material. 58 A precursor phase was precipitated and then dried in vacuo. The resulting powder was decomposed at 200 C then heated to 800 C for 24 hours under oxygen £ow.…”

Recent Progress in Calix[n]quinone (n=4, 6) and Pillar[5]quinone Electrodes for Secondary Rechargeable Batteries

“…Generally, carbon materials, such as graphite ( C theo =372 mAh g −1 ), are selected as anodes in LIBs, whose capacity is much higher than those of common inorganic cathode materials ( e. g . LiCoO 2 , LiMn 2 O 4 and LiFePO 4 ). In this situation, the capacities in both electrodes are not balanced and the relatively low capacity of inorganic cathode materials (around 140–170 mAh g −1 ) will affect the actual reversible capacity and cycle performance of batteries .…”