Solar Energy Materials & Solar Cells 208 (2020) 110344 Available online 7 January 2020 0927-0248/© 2020 Elsevier B.V. All rights reserved. Advances in the development of latent heat storage materials based on inorganic lithium salts Y.E. Milian a , S. Ushak a, * , L.F. Cabeza b , M. Grageda a a Department of Chemical Engineering and Mineral Processing and Center for Advanced Study of Lithium and Industrial Minerals (CELiMIN), Universidad de Antofagasta, Campus Coloso, Av. Universidad de Antofagasta, 02800, Antofagasta, Chile b GREiA Research Group, INSPIRES Research Centre, Universitat de Lleida, Pere de Cabrera S/n, 25001, Lleida, Spain A R T I C L E INFO Keywords: Lithium salts Inorganic latent heat storage Density Thermal properties Eutectic mixtures ABSTRACT Recently, inorganic thermal energy (TES) storage materials to support renewable energy implementation are being developed, and lithium salts have been showing thermal properties suitable for latent storage applications. There are three main technologies to achieve TES: sensible, latent, and thermochemical energy storage. Latent heat storage materials or phase change materials (PCMs) can store large amounts of heat per volume and they can be applied at a certain temperature, depending on the desired application. Lithium compounds for sensible storage have been reviewed in previous publications. Their use in latent heat storage applications is increasing but scarcely documented; while new latent heat storage Li materials appear consistently, the information on them is still dispersed. Therefore, the main objective of this study is to discuss lithium compounds used, proposed or analyzed for latent heat storage (LHS) and their possible applications. Lithium salts thermophysical properties, such as density, melting temperature and latent heat were tabulated as found in literature. Binary salts presented attractive heat of fusion values over 130 kJ kg 1 in a wide range of temperatures. Moreover, the increase of stability of multi-component PCM systems due to the insertion of lithium compounds was confrmed. The technologies to produce lithium are improving and, if the demand increases, prices could decrease in the near future. Therefore, the availability of lithium materials was also analyzed in this study. Finally, potential appli- cations of these thermal storage materials, such as heated underwater diver suits, portable thermal conditioning jackets, solar receiver space, Stirling engines, etc. were assessed. 1. Introduction Lithium, used primarily for batteries, was included in the 2018 Final List of 35 Minerals Deemed Critical to U.S. National Security and the Economy [1]. The report also revealed options for accessing critical minerals through trade with allies and partners, which enforces the importance of this metal at a global level. Due to continuous exploration, lithium resources increased worldwide (more than 53 million tons). 1.1. Lithium resources and markets Three spodumene (LiAlSi 2 O 6 ) exploitation in Australia and two brine exploitations in Chile and Argentina are accountable for the majority of world lithium production (Fig. 1). The leading Chilean lithium producer publicized a joint project with a company in Australia and with a company in Argentina to develop a brine exploitation. Therefore, Australia scheduled to double its spodumene concentrate yield to 1.34 million tons per year by mid-2019 [1]. The leading Argentinean lithium producer extended his LiOH yield by 80% in 2017. Furthermore, an integrated system dynamics model LITHIUM [2] predicted a maximum level of lithium extraction to be reached in 2060, followed by a slow decline in extraction. Lithium shortages and high costs can be dealt before the year 2100 by implementing a new resource management policy, with signifcantly improved recycling to reduce irreversible lithium losses [2]. Meanwhile, the world lithium market is quickly rising, though it is fundamentally still in its early stages [3,4]. Lithium is an indispensable element in the manufacture of the electrode materials for batteries. It is also widely used in the felds of ceramic glass, enamels, warfare, adhe- sive, lubricant greases, medicine, metal alloys, air-conditioning, and dyeing (Fig. 1) [4,5]. The automotive market with lithium-ion batteries * Corresponding author. Department of Chemical Engineering and Mineral Processing and Center for Advanced Study of Lithium and Industrial Minerals (CEL- iMIN), Universidad de Antofagasta, Campus Coloso, Av. Universidad de Antofagasta, 02800, Antofagasta, Chile. E-mail address: svetlana.ushak@uantof.cl (S. Ushak). Contents lists available at ScienceDirect Solar Energy Materials and Solar Cells journal homepage: http://www.elsevier.com/locate/solmat https://doi.org/10.1016/j.solmat.2019.110344 Received 9 May 2019; Received in revised form 2 December 2019; Accepted 5 December 2019