3D all-solid-state batteries: a challenging route towards autonomous integrated power devices

W. Xu¹, D. Danilov¹, L. Gao¹, J.F.M. Oudenhoven², I. Kokal¹, H.T. Hintzen¹,
M. E. Donders^1,3, H.C.M. Knoops^1,3, M.C.M. van de Sanden¹, W.M.M. Kessels¹,
K. Kumar¹, I.S. Pop¹, V. Pop² and P.H.L. Notten¹

¹ Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
² IMEC/Holst Centre, 5656 AE Eindhoven, The Netherlands
³ Materials innovation institute M2i, 2600 GA Delft, The Netherlands

Abstract

Micro-batteries are expected to become more and more important in numerous small-sized devices, like medical implants, biosensors, hearing aids and autonomous network devices. Characteristic for these electronic applications is that they have to operate autonomously and reliably. Due to these requirements the thin film power source needs to be rechargeable, mechanically stable for a long period of time and have an extremely long cycle life. As the average energy consumption of these future devices will be rather small, this opens up the possibility to integrate all-solid-state rechargeable batteries, enabling a high degree of IC integration.
It has been reported that all-solid-state, Li-based, rechargeable batteries can be charged and discharged more than 10,000 times without significant degradation. These thin-film batteries are, however, planar-structured, resulting in a relatively low energy density. By depositing the complete battery stack in a 3D etched substrate, obtained by, for example, physical or wet-chemical etching of mono-crystalline Silicon-wafers, the effective energy and power density can be tremendously increased. Moreover, utilizing novel battery anode materials with a very high storage capacity comprising of thin films electrodes are highly beneficial.
Silicon wafers are common substrates in the semiconductor industry and also the anisotropic etching of several 3D geometries (e.g. pores, trenches and pillars) using reactive ion etching is a mature technique. The step conformal deposition of battery layers into these structures require non-line of sight techniques which are, on one hand, established in the production of integrated devices but are, on the other hand, still quite unexplored for the deposition of battery materials. These methods include Chemical Vapor Deposition (CVD) and Atomic Layer Deposition (ALD). In this presentation the concept of the 3D-integrated battery will be discussed and the highlights of the deposition of the individual layers and the (electro)chemical characterization will be discussed.
In order to operate these devices autonomously, electricity generating is also essential. In the case of autonomous network devices several harvesting methods can be applied based on, for example, solar energy, vibration energy and temperature gradients. In the case of medical implants this is generally no option. However, it has been identified that in this case bio-inspired fuel cells might offer interesting options. Therefore our research has been extended into this direction. In the presentation the basic principles of glucose-based bio-fuel cells will be outlined. Especially the various (electro)chemical steps that has been identified and has been studied from a kinetic point of view.

Biography

Peter H.L. Notten, PhD
Professor

Peter H.L. Notten was born in The Netherlands in 1952, was educated in analytical chemistry and joined Philips Research from 1975 to 2010. While working at these laboratories on the electrochemistry of etching of III-V semiconductors he received his PhD from the Eindhoven University of Technology in 1989. Since then his activities have been focusing on the research of hydride-forming (electrode) materials for application in rechargeable NiMH batteries, switchable optical mirrors and gas phase storage, and Lithium-based rechargeable battery systems. Since 2000 he has been appointed as (part-time) professor at the Eindhoven University of Technology in the faculty Chemical Engineering and Chemistry where he is heading the group Energy Materials and Devices. His main interest includes the development of (i) advanced battery and hydrogen storage materials, (ii) new battery technologies, (iii) modeling of energy storage materials and complete rechargeable battery (NiMH and Li-ion) systems, (iv) the development of sophisticated Battery Management Systems (BMS) and (v) more recently the development of bio-inspired fuel cells in collaboration with the Holst Centre Eindhoven.
He is member of the Dutch Research Platform of Sustainable Energy (NODE), chairman of the working-group Electrochemistry of the Royal Dutch Chemical Society (KNCV) and Member of the Editorial Advisory Board of Advanced Energy Materials and the International Journal of Electrochemical Science. He is involved in the coordination of the Centre-of-Excellence Sustainable Energy Technologies, a collaboration between the three Dutch Technical Universities within the Federation 3TU. He is member of the American Chemical Society (ACS), The ElectroChemical Society (ECS), International Society of Electrochemistry (ISE) and Royal Dutch Chemical Society (KNCV). He has published as (co)author about 150 scientific papers and contributions to scientific books and owns more than 10 US-patents.