## 1 Introduction
Moreover, when the temperature decreases, the electrolyte becomes more and more viscous, thus allowing the delay of PbSO\({}_{4}\) formation, which, combined with the efficiency decrease due to the low temperature, leads to the freezing of the container, which can cause damage to the plates [11]. Therefore, although lead-acid battery (LAB) is the oldest electrochemical energy storage system, its diffusion in new and emerging sectors of technological interest is inhibited by its negative aspects. To overcome these problems, and considering that the electrochemical reactions inside the cell take place mainly on the active surface of the electrode, which is exposed to the electrolyte, a promising solution to improve the performance of lead-acid batteries is to replace conventional electrode plates with innovative electrodes made of nanostructured active materials, that ensure both a high surface area and greater accessibility of the electrolyte within the active material. This research aims at maximizing the surface area of the LAB electrodes to optimize the utilization of the active material present in the cell, therefore enhancing the performance of lead accumulators, and obtaining a competitive device in areas where other technologies (e.g., lithium batteries and supercapacitors) are commonly used. An important battery requirement, in addition to high specific energy, is long lifetime under continuous cycling at HRPSoC owing to the intermittent operation for applications, such as in Full Electric Vehicles (EVs), where the weight also matters. Such a requirement today is fully satisfied by Li-ion batteries, which are, however, unsafe, and currently highly expensive [12; 13]. For off-grid applications and renewable energy storage that is stationary in nature, the weight of the battery is unimportant. In these fields, there is a great opportunity for batteries alternative to lithium-ion that use abundant raw materials. Specifically, zinc-ion rechargeable batteries have recently received much attention owing to the high abundance of zinc in natural resources, intrinsic safety and cost, when compared with the lithium-ion batteries. Attempts to develop rechargeable aqueous zinc-ion batteries (ZIBs) can be traced to as early as the 1980s; however, since 2015, the research activity in this field has surged throughout the world. Despite the achievements made in exploring electrode materials so far, significant challenges remain at the material level and even on the whole aqueous ZIBs system [14; 15; 16]. In this context, LABs are still a valid alternative, and the possibility of optimizing their performance in terms of energy density and rate of charge and discharge is still an interesting solution for the medium term. The subject dealing with the lead-acid battery performance at HRPsoC has been extensively investigated, and different solutions were proposed, such as modifying the negative active material composition through suitable additives, designing innovative assembly with a super-capacitor or improving the energy efficiency through proper managing of the charging process [17; 18; 19; 20; 21]. The ultimate goal is to increase the energy density in order to enhance the performance of lead-acid batteries. These goals can be achieved thanks to the use of polycarbonate membranes with interconnected pores, that permit to realize nanostructured Pb and PbO\({}_{2}\) electrodes, through the template electrodeposition method, that are characterized by a very high active surface. In our previous works, these types of nanostructured electrodes have been tested, obtaining excellent results [12; 22; 23]. In this work, we show some preliminary results obtained from tests carried out on nanostructured electrodes at different temperatures. In particular, we will show that they are able to work, even under stress conditions, at high charge/discharge rates (from 1 to 10 C) and at temperatures from \(-\)20 to 40 \({}^{\circ}\)C.