## 1 Introduction
Among various attractive candidate materials for electrodes, the selection of cathode materials depends on the battery type, i.e., Li\({}^{+}\) or Li-metal batteries. In the case of LIBs, air-stable lithium-based intercalation compounds should be used as a cathode due to the absence of lithium in the anode [33; 34; 35]. On the contrary, for Li-metal batteries, the cathode does not need to be lithiated before cell assembly owing to the use of metallic lithium as an anode [36]. Among a large number of materials proposed for the cathode in LIBs, transition metal oxides have been recognized as one of the most promising cathode materials [37; 38; 39]. For the anode, graphitic carbon allotropes were mostly used in LIBs, but the use of lithium metal can significantly increase the volumetric energy density by up to 70% with respect to graphite (Figure 1) [40; 41]. However, lithium metal electrodes encounter formidable challenges such as uncontrollable dendrite growth and high reactivity with solid electrolytes, which hampers the use of lithium metal electrodes [20]. Alternatively, recent studies of anode materials have focused on lithium transition metal oxides, vanadium oxides or lithium metal nitrides [42; 43; 44]. One of the key features of SSBs is replacing liquid electrolytes with solid electrolytes, which can dramatically enhance the safety of batteries. In order to replace the current organic liquid electrolytes, solid-state electrolytes need to possess high ionic conductivity, negligible electronic conductivity and good stability in contact with the anode and cathode electrodes [45; 46]. Many different types of inorganic solid electrolytes--Na superionic conductor (NASICON) [47], perovskite [48], lithium phosphorous oxy-nitride (LiPON) [49; 50; 51], sulfide [52; 53; 27] and garnet [54; 55; 56]--are widely studied in SSBs. With the development of SSBs, all-solid-state thin-film batteries (SSTFBs) have received significant attention in recent years [57; 58; 59] that can be used for low power microelectronic devices (e.g., implantable medical devices) and energy harvesting technologies [60]. Similar to conventional LIBs, SSTFBs consist of a cathode, an anode and an electrolyte. Owing to the difference in chemical potentials of lithium in the two electrodes, the transfer of Li\({}^{+}\) from the anode through the electrolyte into the cathode (discharge) delivers energy, whereas the reverse lithium transfer (charge) consumes energy. One unique feature of SSTFBs is the usage of nanostructured thin films and thus SSTFBs can significantly reduce the transport distance of charge carriers, enhancing the kinetics of lithium storage [61; 62]. Furthermore, the overall performance of SSTFBs can be controlled by modulating the physical and chemical properties of thin films. In order to make SSTFBs, all the battery components need to be fabricated into multilayered thin films by suitable thin-film techniques. While SSBs and SSTFBs have shown their potential as the next major advances beyond LIBs, their performances have not yet been reached the practical level mainly due to the limits of intrinsic material properties. Therefore, understanding and controlling the properties of electrode and electrolyte materials will provide insight into the enhancement of the next-generation battery performances. Despite several available reviews of SSBs, most efforts have primarily focused on progress in the solid-state electrolytes [55; 76; 77; 78; 79]. Indeed, only a few comprehensive reviews [80; 81; 82] on thin-film electrodes and electrolytes for SSTFBs are available. In this review, we aim to provide a synopsis of the major developments and achievements in electrode and electrolyte materials in both bulk and thin-film forms for SSBs and SSTFBs, which can facilitate the development of high-performance electrochemical energy storage systems. First, we discuss recent progress in bulk-based cathodes, anodes and electrolytes for lithium-based batteries.