A first principles investigation of new cathode materials for advanced lithium batteries

Abstract

First principles calculations on the crystal and electronic structure of a layered Li(Ni 1/3 Mn 1/3 M 1/3 )O 2 (M = Al, Ti, Cr, Fe and Mo) were undertaken as part of a search for new positive electrode materials for advanced lithium ion batteries. The formal charge of Ni, Mn and M (Ti and Mo) were estimated to be +2, +3 and +4, respectively, from electronic structures and interatomic distances. In the cases of the Al, Cr and Fe substitution, the compounds had trivalent M and tetravalent Mn ions. The solid-state redox reactions of Li(Ni 1/3 Mn 1/3 M 1/3 )O 2 were calculated assuming a Li deinsertion scheme, and the reactions were shown to be Ni 2+ /Ni 3+ /Ni 4+ and M 3+ /M 4+ for the Cr and Fe substitution. Al substitution will lead to higher voltages, as fixed 3+ valence of Al forces more electron exchange with oxygen. The cases of Ti and Mo substitution, Ti and Ni ions do not participate in the redox reactions over the entire range, respectively. The substitutive cation-oxygen bonding has a more covalent character, when the redox energy of Ni is lowered, resulting in an increase in potential. As described above, the voltage profiles are very different because the types of metals are different and participate in electrochemical reactions according to the substituted.

Electrochemical Utilization of Iron IV in the Li1.3Fe0.4Nb0.3O2 Disordered Rocksalt Cathode

“…A lot of attention was given to LiFeO 2 polymorphs, [1,2,4–10] yet many of these systems show poor capacity retention, and a large voltage hysteresis. In addition, the LiFeO 2 ‐type cathodes have a lower average discharge voltage (<3 V) than the Ni‐based LiMO 2 cathodes (3.5–4.0 V), even though the Fe 3+/4+ and Ni 3+/4+ redox couples are predicted around a similar potential [11–13] . These performance issues are often attributed to the inability of Fe 4+ to stabilize within LiFeO 2 [2,3] resulting in cycling involving the lower voltage Fe 2+/3+ redox couple instead.…”

“…In addition, the LiFeO 2 -type cathodes have a lower average discharge voltage (< 3 V) than the Ni-based LiMO 2 cathodes (3.5-4.0 V), even though the Fe 3 + /4 + and Ni 3 + /4 + redox couples are predicted around a similar potential. [11][12][13] These performance issues are often attributed to the inability of Fe 4 + to stabilize within LiFeO 2 [2,3] resulting in cycling involving the lower voltage Fe 2 + /3 + redox couple instead. Interest in Fe-based cathodes has been reignited by the growth of novel alkali-rich systems with excess capacities beyond the traditional transition metal (TM) redox couples.…”

Between Scylla and Charybdis: Balancing Among Structural Stability and Energy Density of Layered NCM Cathode Materials for Advanced Lithium-Ion Batteries

“…2,6 Extraction of Li proceeds mainly through oxidation of Ni and Co, 7 yet the Ni ions are believed to be the main redox active species in the voltage range between 3.0 and 4.2 V (vs graphite). 8 Thus, increasing substitution of Ni by both Mn and Co leads to a decrease in specific capacity. 9 For example, LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM111) delivers a specific capacity of about 150 mAh/g for U max = 4.2 V (when cycled against graphite, or U max = 4.3 V when cycled against lithium), which is not sufficient for long-range EVs though.…”

Electrical properties of lead zirconate titanate thick films prepared by hybrid sol–gel method with multiple infiltration steps

“…Typically, the annealing temperatures in the range 500-700 • C are used for the deposition, thus allowing incorporation of ceramic layers into a standard IC technology [1,2]. In addition, the low processing temperatures are advantageous to reduce the interdiffusion of atomic species between different layers and to prevent lead volatilization in Pb-based materials [2,3]. Using this method, lead zirconate titanate (PZT) thin films are being routinely deposited onto variety of substrates in view of their perspective piezoelectric applications including pressure sensors, accelerometers and micromotors [4].…”