Long-term stability is one of the most desired functionalities of energy storage microdevices for wearable electronics, wireless sensor networks and the upcoming internet of things. Although Liion microbatteries have become the dominant energy-storage technology for on-chip electronics, the extension of lifetime of these components remains a fundamental hurdle to overcome. Here, we develop an ultra-stable porous anode based on SnAu alloys able to withstand a high specific capacity exceeding 100 µAh cm −2 at 3 C rate for more than 6000 cycles of charge/discharge. Also, this new anode material exhibits low potential (0.2 V versus lithium) and one of the highest specific capacity ever reported at low Crates (7.3 mAh cm −2 at 0.1 C). We show that the outstanding cyclability is the result of a combination of many factors, including limited volume expansion, as supported by density functional theory calculations. This finding opens new opportunities in design of long-lasting integrated energy storage for self-powered microsystems.

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

No abstract

An analytical ab initio-based model for adsorption isotherm is presented. As input data, this model takes the adsorption Gibbs free energies of different possible coverages within a reasonably large unit cell. In this way, the lateral interactions between adsorbates and their dependence on temperature are included. The self-dependence of surface coverage is taken into account via the introduction of heterogeneity of adsorption and the use of an appropriate configurational partition function. The model reproduces the isotherm and selectivity (for binary gas mixtures) of ab initio-based grand-canonical Monte Carlo simulations. The presented isotherm has a moderated dependence on the width of the chosen ab initio unit cell, particularly for high surface loading. This isotherm seems to be a very good approximation for the grand-canonical solution, depending on the accuracy and completeness of the ab initio data.