Enhanced performance of lithiated cathode materials of LiCo _{0 . 6} X _{0 . 4} O ₂ (X = Mn, Sr, Zn) for proton‐conducting solid oxide fuel cell applications

Abstract

LiCoO 2-based materials are well-known cathode materials used in lithium ion batteries. Moreover, these materials are currently utilized in low-temperature proton-conducting solid oxide fuel cells (SOFCs). Various dopants, such as Mn, Sr, and Zn, are introduced into LiCo 2-based materials to improve their properties and performance for proton-conducting SOFC applications. In this regard, Mn-, Sr-, and Zn-doped LiCoO 2 and LiCo 0.6 X 0.4 O 2 (X = Mn, Sr, or Zn) powders are synthesized via the glycine-nitrate combustion method. Their properties are characterized using different techniques. The precursor cathode powder is dried at 100 C and subjected to thermogravimetric analysis (TGA). The phase formation and morphology of calcined LiCo 0.6 Mn 0.4 O 2 (LCMO), LiCo 0.6 Sr 0.4 O 2 (LCSO), and LiCo 0.6 Zn 0.4 O 2 (LCZO) powders at 600 C to 700 C are examined via X-ray diffraction. At 600 C, both calcined LCSO and LCZO powders show few secondary phases, but these phases greatly decrease as calcination temperature increases to 700 C. By contrast, calcined LCMO powders exhibit a single phase structure at both calcination temperatures of 600 C and 700 C. The measured crystallite sizes of LCMO, LCSO, and LCZO powders are 23.32 ± 0.20, 21.08 ± 0.72, and 21.24 ± 0.32 nm, respectively. TEM images indicate that the particles in LCMO and LCZO powders highly agglomerate compared with those in LCZO powders. This result confirms that LCSO cathodes have the highest electrical conductivity (356.66 S cm −1) and the lowest area specific resistance (0.29 Ω cm 2 in humidified [3%] air) at 700 C. In conclusion, LCSO materials are the best cathodes with high potential for protonconducting SOFC applications.

Scientometric review of advancements in the development of high-performance cathode for low and intermediate temperature solid oxide fuel cells: Three decades in retrospect

“…Later, mixed ionic and electronic conductors (MIEC) were developed as a cathode as the electrochemical reaction region can be extended from the TPB to the entire surface of the MIEC cathode [112][113][114][115][116][117][118][119][120][121]. To shed light on this aspect, Adler [85] has extensively discussed mechanisms on how ORR takes place at the cathode and the roles material properties and microstructure play in this regard.…”

“…However, one of the key challenges identified with protonic SOFCs is the lower power output compared to anion conducting SOFCs. Although there have been significant efforts by researchers to improve the cathode for proton-conducting ceramic fuel cells (PCFC), also known as proton-conducting solid oxide fuel cells as reported in some recent classic articles [4,5,[109][110][111][112][113][114][115][116][117][118][119][120][121][122][123], more strategic and collaborative efforts need to be exercised to develop cathodes with efficient triple conductivity (i.e proton, electron, and oxygen ion conduction capacity). Another major challenge identified with protonic SOFCs is the formation of water at the cathode which is not good for the cell.…”

Comparative Analysis of LiCo0.6Sr0.4O2 Cathode Electrochemical Performance in Oxide- and Proton-Conducting Intermediate-Temperature Solid Fuel Oxide Cells

“…Various methods are employed by researchers to produce high-quality cathode coatings, including manual mixing, ball milling, and triple-roller milling (TRM) methods [3][4][5]. The cathode ink produced using the TRM method is known to be capable of providing a cathode film with a more homogeneous particle distribution [6,7].…”

Entropy engineering design of high-performing lithiated oxide cathodes for proton-conducting solid oxide fuel cells

“…If lithiated oxides can be used in H-SOFCs, the materials between Li-ion batteries and SOFCs can be bridged, and the mass manufacturing of lithiated oxides in the Li-ion battery industry can be utilized in the fuel cell field. Only a few studies have been conducted to date to study the performance of lithiated oxide cathodes for H-SOFCs, demonstrating that the performance of lithiated oxide cathodes is low [21,22], indicating a significant problem in utilizing lithiated oxides for H-SOFCs. Although it has recently been discovered that the inclusion of the Co 3 O 4 second phase can improve the performance of LiCoO 2 for H-SOFCs, the improvement is primarily based on the creation of the LiCoO 2 /Co 3 O 4 interface rather than the enhanced catalytic activity of the lithiated oxide [23].…”