1.1 Introduction
Currently, rechargeable lithium-ion battery (LIB) is the fastest growing energy storage device. It dominates portable and smart electronic devices such as cellular phones, laptop computers, and digital cameras due to its light weight, high energy density, good capacity retention, and long lifespan (Jiantie Xu et al. 2017, 1–14; Qi Wen et al. 2017, 19521–19540; K. Liu et al. 2018, eaas 9820). Tremendous research efforts led to its commercialization by SONY 29 years ago (1991), and these material-driven research efforts have led to significant improvement in the electrochemical performances of LIB. Lithium-ion batteries are now safer, have higher energy capacity, better cycling stability, and highest energy density compared to other common secondary batteries such as lead-acid, nickel-cadmium, and nickel-metal hydride. A greater part of this progress can be ascribed to the search and introduction of new materials with improved properties. LIBs are still the most promising option for large-scale energy storage for electric vehicles (EVs), hybrid electric vehicles (HEVs), grid-scale energy storage, and critical space and aeronautical applications (Jiantie Xu et al. 2017, 1–14; Qi Wen et al. 2017, 19521–19540; X. Lou et al. 2019, 6089–6096). The quest to use LIB for these higher energy storage applications will continue to challenge performance of LIBs and to drive the search for improved LIB materials.
The electrochemical performance of LIB is critically dependent on the intrinsic nature of electrode materials and chemistry associated with electrode–electrolyte interface. Besides the inherent nature of electrode materials which include physical and chemical properties, performance depends also on the design and synthesis routes for the electrode materials, which can enable modification of composition or structures, reduction in defects or creation of performance-enhancing architectures (Qi Wen et al. 2017, 19521–19540). The early development of rechargeable LIBs had material challenges associated with intrinsic reactivity of lithium metal, which posed safety and rechargeability problems. This initial problem was reduced by incorporating pure lithium metal into weakly bonded compounds such as graphite, to form intercalated lithium ion electrode that is slightly lower in energy density than pure lithium metal, but less reactive and safe.
Over time due to increasing demand for better performance, there has been intense and progressive research effort to overcome many of the LIB material problems by designing and developing a variety of new anode, cathode, and electrolyte materials. Materials that have been studied as anode materials include metallic lithium (K. Xu 2004, 4303–4418; B. Scrosati B 2011, 1623–1630), various forms of carbon (N. Nitta et al. 2015, 252–264; Z. Yan et al. 2017, 495–501; H. Zheng et al. 2012, 4904–4912; C. Ma et al. 2013, 553–556; K. Wang et al. 2017, 1687–1695), and other materials based on silicon (Si) (N. Nitta et al. 2015, 252–264; A. Casimir et al. 2016, 359–376), tin (Sn) (O. Crosnier et al. 1999, 311–315), titanium (Ti) (N. Nitta et al. 2015, 252–264; S. Chauque et al. 2017, 142–155), and conversion reaction-type materials (J. Cabana et al. 2010, E170–E192; Scrosati and Garche 2010, 2419–2430; Y. Lu et al. 2018, 972–996). The major cathode materials include layered lithium transition metal oxides of the types LiMO2 (M = V, Cr, Mn, Fe, Co, N) [Y. Yang et al. 1997, 227–230, J. Shu et al. 2010, 3323–3328), LiFePO4 (L.H. Hu et al. 2013, 1687; C.T. Hsieh et al. 2014, 1501–1508), V2O5 (Y. Yang et al. 2014, 9590–9594), non-oxide FeS2 (D.T. Tran et al. 2015, 87847–87854), fluoride-based compounds, and poly-anionic compounds (electronic conducting polymers) (Sngodu, Deshmukh 2015, 42109–42130; T.M. Higgins et al. 2016, 3702–3713).
Though these research efforts have resulted in the production of higher capacity and safer LIBs, but the realization of electrode materials with optimum electrochemical performances, ease of synthesis, and manufacture for massive energy storage is still pending. This chapter reviews the research efforts and challenges in the progressing development of new anode and cathode electrode materials in response to the increasing demand for cheaper, safer, lighter, higher energy storage capacity, and environmentally friendly LIBs.
1.2 Brief History of Lithium-Ion Battery Materials
The use of lithium metal as battery anode electrode material started much earlier than now due to its attractive properties such as low density (0.534 gcm‒3), high specific capacity (3860 mAhg‒1), low redox potential (−3.04 V vs. SHE), and low resistance (Krivik and Baca 2013; Mogalahalli 2020, 1884). These properties result in significantly high energy density and high operating voltage in lithium- based batteries compared to traditional batteries such as lead-acid, nickel-cadmium, and nickel-metal hydride batteries. The design of non-rechargeable or disposable lithium-metal battery started around 1912, and the first primary lithium batteries were commercially available in the early 1970s (Lewis and Keyes 1913, 340–344; Krivik and Baca 2013). Such primary non-aqueous LIBs included lithium sulphur dioxide Li//SO2 which was introduced in 1969 (Meyers and Simmons 1969); lithium-carbon monofluoride (Li//CFx) primary cell introduced in 1973; lithium-manganese dioxide primary cells (Li//MnO2) which came into being in 1975, and lithium-copper oxide Li//CuO batteries (Goodenough 2013, 51–92). These early primary Lithium cells found applications in LED fishing floats, cameras, calculators, and memory backup applications.
The increasing demand for batteries of higher performance and the drive to harness the attractive properties of lithium metal attracted great research efforts towards converting lithium primary cells into rechargeable cells with high energy density. These attempts to develop rechargeable lithium batteries had challenges such as safety problems associated with high chemical reactivity of lithium metal and the tendency for lithium to precipitate on the negative electrode during charging forming dendrites which easily cause short circuiting (Akira Yoshino 2012, 2–5). Lithium is a very reactive rare-earth metal, and this characteristic poses problems not only in manufacture but also in the selection of other battery components.
The difficulties of working with pure lithium metal were reduced with the discovery of intercalation compounds or non-stoichiometric compounds or weakly bonded compounds by inorganic and solid-state chemists in the 1970s (Guerard and Herold 1975, 337–345; Whittingham 1978, 41–99), which gave birth to rechargeable LIBs. This enabled intercalation reactions of an ion, atom, or molecule into a crystal lattice of a host material without destroying the crystal structure (Akira Yoshino 2012, 2–5). Lithium atoms were incorporated in the weakly bonded layers of these compounds forming intercalated compounds (non-metallic Li-based compounds). Although, intercalated lithium ion is slightly lower in energy density than pure lithium metal, it is safer. Both anode and cathode materials were made of lithium intercalated compounds such that lithium ions could intercalate and de-intercalate in the ...
