The study of aluminium anodes for high power density AL-air batteries with brine electrolytes

In this thesis aluminium alloys containing small additions of both tin (~ 0.1 wt %) and gallium (~ 0.05 wt %) dissolve anodically at high rates in brine media; at room temperature, current densities > 0.2 A cm-2 can be obtained at potentials close to the open circuit potential, ~ -1.5 V vs SCE. Alloys without both tin and gallium do not dissolve at such a negative potential. The tin exists in the alloys as a second phase, typically as ~ 1 ?m inclusions throughout the aluminium structure. Anodic dissolution leads to rounded pits around the tin inclusions. The pits are different in structure from the crystallographic pits observed with Al and other alloys. Clearly, the AlMgSnGa alloys dissolve by a different mechanism. Although the distribution of the gallium in the alloy could not be established, it is essential to the formation of these pits and maintaining dissolution. In addition to the composition, mechanical working and heat treatment influence both the stability of the alloys to open circuit corrosion and the overpotential for high rate dissolution, factors critical to battery performance. The correlation between performance and alloy microstructure has been investigated. Imaging with a high speed camera with a resolution of 10 – 20 ?m was used to observe the dissolution of AlMgSnGa alloys. Using microelectrodes with only a few Sn inclusions in their surface, allows confirmation that hydrogen evolution occurs only from the Sn inclusions and also showed that the evolution of H2 is not continuous. Therate of H2 evolution correlates with shifts in potential between - 1.5 V and much less negative potentials. The performance of a laboratory Al-air battery with 2 M NaCl electrolyte was limited by both the performance of the O2 cathode and the extent of dissolution of the alloy. Using a cell with a low electrolyte volume/surface area ratio, dissolution of the anode stopped after the passage of 1000 C cm-2 due to a high impedance, thick film of crystals clinging to the surface. Removal of this film allowed the dissolution to recommence. The charge limitation depends on cell design but a high charge density would be difficult to achieve with a low volume battery

Battery Simulation Tool for Worst Case Analysis and Mission Evaluations

Saft recently designed, developed and qualified in the frame of Research and Development contract (GSTP-5) with the European Space Agency (ESA) three new VES16 batteries: 8S4P (4 parallel strings of 8 cells in series), 10S5P, 10S16P [ 1 ]. In order to guarantee the cells balancing (to avoid cell overcharge or over discharge during battery charge/discharge cycles), Saft introduced in parallel of each cell a simple electronic circuit called the Simplified Balancing System (SBS), which absorbs some current when a cell is close to its end of charge voltage. The complete batteries (cells and SBS) were analysed with a proper Worst Case Analysis (WCA) to demonstrate the battery performance at the EOL of the targeted missions, including all possible effects that can influence its behaviour (cells and SBS components initial tolerances, radiation degradations, ageing and temperature effects). Saft performed this analysis in PSpice and developed VES16 cell model and SBS models to run Monte Carlo Analysis (MCA). The first part of this paper presents the PSpice models including their respective variable parameters at SBS and cell level. Then the second part of the paper introduces to the reader the model parameters that were chosen and identified to perform Monte Carlo Analysis simulations. The third part reflects some MCA results for a VES16 battery module. Finally the reader will see some other simulations that were performed by re-using the battery model for an another Saft battery cell type (MP XTD) for a specific space application, at high temperature

In-Orbit Trend Analysis of Galileo Satellites for Power Sources Degradation Estimation

This paper presents the IOV and FOC Battery in orbit trend analysis and degradation modelling based on the Galileo experience in the frame of the ESPC 2016. Galileo provides a unique opportunity to study a constellation of satellites in the Medium Earth Orbit (MEO) to make a statistical analysis of power sources degradations due to its environment. From a project point of view the objective of the study is to establish a process to obtain the in-orbit battery degradations. Accurate battery degradation knowledge will allow precise battery management from operation teams (battery fade strategy and combined Earth Lunar eclipse power estimations). Another key feature of this study is to be able to assess different battery performance (Saft and ABSL) under very similar mission requirements over a long period (electrical profile, temperature, and environment). This paper reports on the first four years in orbit of IOV PFM satellite (10 eclipse seasons and still running) and on-going FOC satellite telemetry (TM) analysis (starting with two years of data from FOC GSAT201 and GSAT202). The results are in all cases better than the predictions, which is expected due to the usage of conservatives assumptions in the design to cover (for both IOV and FOC) worst case scenario for the entire constellation. It should be noted that the FOC GSAT201 and GSAT202 batteries are degrading slightly faster than the 6 others FOC batteries identified GSAT203, GSAT204, GSAT205, GSAT206, GSAT208 and GSAT209, but still below predictions due to their peculiar unexpected orbit reached after launch (higher DoD up to 42% measured due to longer eclipses). These 2 satellites will require specific degradation monitoring

Beyond Lithium-Ion: Lithium- Sulphur Batteries for Space?

Lithium-ion (Li-ion) batteries are established as the state of the art [1] rechargeable batteries for terrestrial and space applications today since the launch of Proba 1 satellite in 2001. [2] At the moment there is strong interest by all stakeholders related or influenced by the battery markets on two systems: The rechargeable Li-air (Li-O2) and Li-Sulfur (Li-S) batteries. There have been many studies on both technologies during the past decades but since major challenges are still to be overcome, none of the two technologies has been yet commercialized. Li-S is believed to reach mass commercialization towards the end of the decade whereas Li-O2 is expected to be available after 2030. Therefore, discussion to follow hereby will focus on Li-S. Li-S cells are regarded as one of the most promising systems for next generation batteries due to their high theoretical capacity, the abundant and low cost sulfur resources and lithium-ion comparable cathode production techniques. [RD3] If Li-S batteries were to be successfully developed and reach their theoretical maximum, batteries over six times lighter than the conventional lithium-ion ones, would be available. [RD4] Sion Power in the US and OXIS Energy Ltd. in Europe are the major companies producing Li-S cells. Prototype Cells were procured from Oxis Energy, UK and characterisation tests were performed at ESA-ESTEC Battery Life Test Facility in Noordwijk, Netherlands. The results are presented here, mainly in order to enhance basic understanding on existing technology in Europe and show relevant trends. Consequences at power system level, if this technology was to be adopted for satellite applications, are also addressed in this paper

High specific energy Lithium Sulfur cell for space application

The battery energy density remains a key parameter accounting for the satellite mass budget. As illustration to this, the rechargeable battery still represents 100 to 200 of kilograms for a typical Eurostar 3000 satellite, which can represent up to 5% of the total mass, and about 100 kilograms for the next meteorological satellite program MetOp-SG. Any reduction in weight in these applications has therefore significant financial benefits, considering that the launch cost for such a satellite can be around 10k€/kg. Lithium-ion technology represented a revolution in terms of specific energy compared to Ni-Cd and is currently the most used and well suited for spacecraft. But it has also many drawbacks like price, some safety issues and its toxicity. Lithium-Sulfur (Li-S) cells are likely to become the next generation of energy storage to replace them. One of the reasons is that sulfur is an abundant element so it’s more affordable than cobalt used in Li-Ion cells. On top of that, Li-S cells are safer and more environmentally friendly. But the main advantage of this technology is the high energy density: around 5 times higher than Li-Ion cells. The major obstacle for application is due to dissolved polysulfide shuttling between anode and cathode. This phenomeno leads to permanent loss of active mass from the cathode into the electrolyte and onto the Li metal anode (passivating the Li anode with insoluble Li2S), severe self-discharge, low efficiency and fast capacity decay. Airbus DS has been testing and characterizing prototype Li-S cells manufactured by OXIS Energy Ltd. since 2014, demonstrating the potential and fast evolution of the cells performance. This paper presents the last test results on a set of different batches provided by OXIS and performed at Airbus DS premises in the frame of an ESA Innovation Triangle Initiative (ITI)

Studies of the anodic dissolution of aluminium alloys containing tin and gallium using imaging with a high-speed camera

Imaging with a high-speed camera at a resolution of 10–20 ?m has been used for the direct observation of the anodic dissolution of aluminium alloys containing Sn and Ga. The imaging allows confirmation that hydrogen bubble evolution occurs from the Sn inclusions within rounded pits during both open circuit corrosion and anodic dissolution. Using microelectrodes with only a few Sn inclusions in their surface, it is shown that the evolution of H2 is not continuous and may be correlated with a potential oscillations between ?1.50 V (where H2 evolution occurs) and significantly less negative potentials (where no H2 is evolved). It is proposed that this potential shift is associated with pH changes resulting from H2 evolution itself

High specific energy Lithium Sulfur cell for space application

The battery energy density remains a key parameter accounting for the satellite mass budget. As illustration to this, the rechargeable battery still represents 100 to 200 of kilograms for a typical Eurostar 3000 satellite, which can represent up to 5% of the total mass, and about 100 kilograms for the next meteorological satellite program MetOp-SG. Any reduction in weight in these applications has therefore significant financial benefits, considering that the launch cost for such a satellite can be around 10k€/kg. Lithium-ion technology represented a revolution in terms of specific energy compared to Ni-Cd and is currently the most used and well suited for spacecraft. But it has also many drawbacks like price, some safety issues and its toxicity. Lithium-Sulfur (Li-S) cells are likely to become the next generation of energy storage to replace them. One of the reasons is that sulfur is an abundant element so it’s more affordable than cobalt used in Li-Ion cells. On top of that, Li-S cells are safer and more environmentally friendly. But the main advantage of this technology is the high energy density: around 5 times higher than Li-Ion cells. The major obstacle for application is due to dissolved polysulfide shuttling between anode and cathode. This phenomeno leads to permanent loss of active mass from the cathode into the electrolyte and onto the Li metal anode (passivating the Li anode with insoluble Li2S), severe self-discharge, low efficiency and fast capacity decay. Airbus DS has been testing and characterizing prototype Li-S cells manufactured by OXIS Energy Ltd. since 2014, demonstrating the potential and fast evolution of the cells performance. This paper presents the last test results on a set of different batches provided by OXIS and performed at Airbus DS premises in the frame of an ESA Innovation Triangle Initiative (ITI)

Erratum to “Further studies of the anodic dissolution in sodium chloride electrolyte of aluminium alloys containing tin and gallium” [J. Power Sources 193 (2) (2009) 895–898]

The publisher regrets that there was an error within Table 1. Please see corrected table.The publisher would like to apologise for any inconvenience this may have caused to the authors of this article and readers of the journal

Further studies of the anodic dissolution in sodium chloride electrolyte of aluminium alloys containing tin and gallium

As part of a programme to develop a high power density, Al/air battery with a NaCl brine electrolyte, the high rate dissolution of an aluminium alloy containing tin and gallium was investigated in a small volume cell. The objective was to define the factors that limit aluminium dissolution in condition that mimic a high power density battery. In a cell with a large ratio of aluminium alloy to electrolyte, over a range of current densities the extent of dissolution was limited to ?1000 C cm?2 of anode surface by a thick layer of loosely bound, crystalline deposit on the Al alloy anode formed by precipitation from solution. This leads to a large increase in impedance and acts as a barrier to transport of ions

Qualification and Life Testing of Li-Ion Ves16 Batteries

In the frame of an ESA GSTP 5.2 activity (contract 4000105105), the qualification and life testing of a Saft range of Li-ion batteries based on VES16 cells and theirs autonomous simplified balancing system (SBS) has been carried out. In this abstract the development, qualification plan and successful results from all various tests conducted on the VES16 qualification battery modules are synthetized. Up to the present time, Saft batteries have been mainly utilizing for space applications high capacity cells, like the 45 Ah VES180 and the 35 Ah VES140 cells, targeting predominantly space missions in Geostationary Earth Orbit (GEO). However following the qualification and commercialization of the Saft 4.5 Ah VES16 cell in October 2011 [1] & [2], Saft has been developing and qualifying in the frame of this ESA GSTP 5.2 contract, VES 16 batteries for space missions, targeting both GEO and Low Earth Orbit (LEO) satellite missions. The electrochemistry of the VES16 cells used for the battery modules under the ESA qualification program is not novel. For VES16 cells, the Saft knowhow from large capacity space cells used for space applications, since SMART 1 mission in 2003, has been tailored for a cell with smaller capacity in order to facilitate the modular philosophy that has been deployed in this battery range