Limitations and Characterization of Energy Storage Devices for Harvesting Applications

Abstract

This paper aims to study the limitations and performances of the main energy storage devices commonly used in energy harvesting applications, namely super-capacitors (SC) and lithium polymer (LiPo) batteries. The self-discharge phenomenon is the main limitation to the employment of SCs to store energy for a long time, thus reducing efficiency and autonomy of the energy harvesting system. Therefore, the analysis of self-discharge trends was carried out for three different models of commercial SCs, describing the phenomenon in terms of self-discharge rate and internal resistance. In addition, physical interpretations concerning the self-discharge mechanism based on the experimental data are provided, thus explaining the two super-imposed phenomena featured by distinct time constants. Afterwards, the dependence of self-discharge phenomenon from the charging time duration (namely, SCs charged at 5 V and then kept under charge for one or five hours) was analyzed; by comparing the voltage drop during the self-discharge process, a self-discharge reduction for longer charging durations was obtained and the physical interpretation provided (at best −6.8% after 24 h and −13.4% after 120 h). Finally, self-discharge trends of two commercial 380 mAh LiPo batteries (model LW 752035) were acquired and analyzed; the obtained results show an open circuit voltage reduction of only 0.59% in the first 24 h and just 1.43% after 124 h.

Self-Discharge of a Proton Exchange Membrane Electrolyzer: Investigation for Modeling Purposes

“…Based on the previous works reported for self-discharge in batteries [ 18 , 20 ] and supercapacitors [ 27 , 28 ], the studied PEM electrolyzer features a higher self-discharge rate. Indeed, lead-acid and lithium-ion batteries feature low self-discharge rates (noticeable in terms of days, weeks, or even months), and supercapacitors higher self-discharge rates (noticeable in terms of hours or days).…”

“…The phenomenon of self-discharge voltage has proven to be an important subject of study for any electrochemical device, particularly for batteries and supercapacitors. For batteries, the self-discharge voltage is the main limitation to storing energy for a long time, so the efficiency and autonomy of systems are poor [ 20 ], which is a challenging issue when using batteries in electric vehicles, industries, and residences [ 21 , 22 ]. To reduce battery self-discharge voltage, many strategies have been developed, such as optimizing materials for battery construction [ 22 , 23 ] and developing different models with a high degree of reliability (i.e., by taking into account several variables or assimilating the battery like an electronic circuit) [ 24 , 25 ].…”

A Stake-Out Prototype System Based on GNSS-RTK Technology for Implementing Accurate Vehicle Reliability and Performance Tests

“…The 12 V voltage is supplied by the output connector able to deliver up to 2 A (VBOX 3iSR max absorbed current is 0.625 A corresponding to 7.5 W power [17]). The 37 Wh capacity ensures a 5 h operation of the VBOX 3iSR INS in the case of maximum current absorption [23]. -GNSS Antenna: model RLACS156 manufactured by Raceologic [24], it is placed on the pole top to obtain a better satellite signals reception (supported frequency band 1574-1606 MHz).…”

Sensors-based mobile robot for harsh environments: functionalities, energy consumption analysis and characterization

“…The mobile robot consumes 9.3 W of power (at maximum speed but without obstacles or energy loss), which are provided by an on-board battery pack consisting of two 9,900 mAh lithium ion (Li-Ion) batteries (the blue cylindrical packages in Figure 6) connected in parallel. These batteries (manufactured by GTF, model TR18650, 3.7 V nominal voltage) ensure an autonomy of more than five hours in the worst-case condition, corresponding to continuous current absorption of 2.5-2.6 A [25]. However, if additional power is required, in case of friction and/or complicated paths, a parallel solar energy harvesting system was installed to automatically boost the robot when needed, as described below.…”