Carbon: A Ubiquitous Electrode Material for Lithium-Based Rechargeable Batteries

Abstract

In recent times, research has been directed to develop high-capacity anodes along with high-energy-density (high capacity and high voltage) and safe Lithium-ion battery (LIB) cathodes to power electric vehicles (EV’s). State-of-the-art lithium-ion cells use layered transition metal oxides (LiCoO2, LiNi1/3Mn1/3Co1/3 or LiNi0.8Co0.15Al0.15O2), or Phosphates (LiFePO4), Mn-based spinels (LiMn2O4) as cathodes and graphitic carbon as anode [1-2]. The nominal capacities of most of these cathodes range between 140-180 mAh g-1 when cycled up to 4.2 V. This is only half the specific capacity of graphite anode (372 mAh g-1). Thus, there has been intense research activity in the last decade to develop high-capacity anodes or high energy (high capacity and high voltage) and safe cathodes for lithium-ion batteries (LIBs) [1-2]. Eliminating binders and carbon diluents and replacing carbon fiber-based 3D electrode architectures can improve the capacity utilization and C-rate performance, thereby improving energy density, cycle life, and safety of LIBs. The presentation will be focused on the development of organic binder and conducting diluent-free carbon fiber-based 3D electrodes architectures for LIBs, where the conventional copper (Cu) and aluminum foil (Al) foil current collectors are replaced with highly conductive carbon fibers (CFs). In this approach, the petroleum pitch (P-pitch) is used as a binder that adequately coats between the CFs and active nanoparticles (NPs) at high temperatures to form a uniform continuous layer of carbon coating along the exterior surfaces of NPs and 3D CFs. As a result, the electrodes assembly delivers superior electrochemical performances than conventional electrode fabrications. 3D electrode architecture of LiFePO4, FeF3, Li2MnSiO4 cathodes, and Si-C anodes will be presented [3-5]. Dual carbon batteries (DCBs) based on LIB electrolytes have been evolving in recent times [5]. In DCBs, both electrodes consist of carbonaceous materials, and the ions from the electrolyte intercalate and deintercalate into the electrode matrix. During the charge, the cations and anions get inserted into the anode and cathode, respectively, and during discharge, the process is reversed. A DCB based on the 3D electrode architecture of carbon (zero transition metal ion) will be discussed. A DCB based on fully graphitic carbon fiber can have a nominal voltage of 4.65 V and can deliver energy densities of 92.7, and 110.9 Wh kg−1 at a power density of 114 W kg−1 for the cells cycled at 3.0–5.0 and 3.0–5.2 V, respectively. It is believed that the study presented here may contribute to the future development of carbon fiber-based dual-carbon and lithium-ion batteries. References 1. The Li-Ion Rechargeable Battery: A Perspective, J. B. Goodenough, K.-S. Park, J. Am. Chem. Soc. 135 (2013) 1167–1176. 2. Promise and reality of post-lithium-ion batteries with high energy densities, J. W. Choi, D. Aurbach, Nature Rev. Mater. 2016, 1, 16013. 3. Synergistic effect of LiF coating and carbon fiber electrode on enhanced electrochemical performance of Li2MnSiO4, S.K. Kumar, S Ghosh, M. Bhar, A. K. Kavala, S Patchaiyappan, S. K. Martha, Electrochimica Acta, 373, 137911 (2021). 4. Nanostructured Silicon−Carbon 3D Electrode Architectures for High-Performance Lithium-Ion Batteries, S. Krishna Kumar, Sourav Ghosh, S. K. Malladi, Jagjit Nanda, S. K. Martha, ACS Omega, 3, 9598−9606 (2018). 5. Multifunctional Utilization of Pitch Coated Carbon Fibers in Lithium Based Rechargeable Batteries, S. Ghosh, U. Bhattacharjee, S. Patchiyappan, J. Nanda, N.J Dudney, and S. K. Martha, Advanced Energy Materials, 2100135 (2021). Figure 1