Microstockage d énergie Les dernières avancées. S. Martin (CEA-LITEN / LCMS Grenoble)

Transcription

1 Microstockage d énergie Les dernières avancées S. Martin (CEA-LITEN / LCMS Grenoble) 1

2 Outline What is a microbattery? Microbatteries developped at CEA Description Performances Integration and Demonstrations On going developements Overview of worldwide developments Main competitors Prototypes 2

3 What is a microbattery? 15 µm Lithium battery Physics similar to classical lithium battery Solid state electrolyte No liquid No leakage High Temperature stability Integrable Thin film battery Realized with thin film deposition facilities Overall thickness : 5-20 µm 3

4 Active stack Different solutions to fit requirements» Li metal or Li-ion» Low Temperature process» Output voltage from 1 to 4 V Anode electrode Li, Si x Ge 1-x (0.1 to5 µm), thermal evaporation or sputtering Solid electrolyte LiPONB (1 to 2 µm), sputtering Cathode electrode TiS x O y, LiCoO 2, V 2 O 5 (2 to 4 µm), sputtering Current collector W, Ti, Pt (0.2 to 0.5 µm), sputtering Substrate 4 to 8 Si wafers Polymers, Ceramic 4

5 Microbattery Performance Standard TiOS/Lipon/Li S = 25 mm² 2.5 µa Capacity (µah/cm²) 5

6 Microbattery Performance Standard TiOS/Lipon/Li TiOS/Lipon/Li 25 mm² on 4 Si wafer Capacity capacity (µah/cm²) (µah) C/10 C 2C 4C 8C 12C 16C 20C C/10= 10 µa/cm² 30C= 3 ma/cm² Cycle number 10 µa/cm 2 during 10 h 3 ma/cm 2 during 50 s 6

7 Microbattery Power capability High duty cycles Standby current: 25 µa Pulse current: 2.5 ma/cm 2 Result 4080 High duty cycles 28 µah/cm 2 to 1V discharge 7

8 Processes involved Barrier layer : PECVD : Conformal, low Temperature Polymer buffer Wet chemistry or Polymer Evaporation High dep rate, good Mechanical properties Active Layers RF or DC sputtering Density, Adhesion, thickness control, low temperature 8

9 Main developments at CEA Integration (QFN Package, autonomous sensors, µuav ) Encapsulation Barrier properties Flexibility Patterning Shadow Masks Maskless Process Active Stack Materials Process Substrate Texturation Flexibiliy 9

10 Encapsulation High barrier required Thin Multilayer stack required H 2 O vap permeability rate (g/m 2 day) Inorganic PV F-OLEDs Food packaging µ Batteries O 2 permeability rate (cm 3 / m 2 day atm) Inorganic Single layer Inorganic/organic Multi-layer polymers Inorganic monolayer Multilayer Lid sealing Ultra high Barrier (UHB) 10

11 Microbattery SEM examination Encapsulation Active layers Substrate Picture from CNRS/ICMCB 1 µm 11

12 Microbattery manufacturing Process development on industrial tool (200mm substrates) Patterning: from Shadow Mask to maskless process 12

13 Substrates Flexible substrates Polyimide subtrates (low T process) Large area for high capacity Textured substrates Stacking of microbatteries 13

14 Integration: Solder reflow capability Electronic market requires possibility to use energy storage as any other component Capability to sustain high temperature step for connection (SR) Microbattery Technology can fulfill the requirement Microbattery cycling before and after 3 Lead free Solder Reflow 14

15 High voltage photolithography microbatteries Objectives: High voltage (> 30V) energy source for rf MEMS Connections in series of 16 V 2 O 5 based microbatteries Photolithographic process Standard clean room environment 100 x 100 µm² microbatteries 200 µm ,0 50 2,5 E (V vs Li + /Li) ,0-2,5 I (na) 10-5, time (sec) 15

16 High voltage microbatteries Objectives: High voltage energy source for actuators Technology fusion between silicon actuators and microbattery Applications: µuav, avionics 16

17 Integration: Above IC capability Microbattery on integrated circuit for smart card application: security improvment 40 mm Microbatteries (23 mm²) 17

18 Autonomous micro-power system Autonomous sensor long life time communication Miniaturization Hybrid micropower system: Storage + Harvesting Microbateries are perfectly suited for these kind of requirements Thin film, integrable High number of cycles w/o lose of capacity Low self discharge Pulse capabilities Generic storage solutions for several energy harvesting systems: PV, thermoelectricity, piezo 18

19 Microbattery Digest Available Microbatterie characteristics Capacity Power Voltage Cyclability Thickness Surface Substrate Safety Up to 300 µah/cm² Up to 5 mw/cm² Between 4.2 and 1 V > Thousands of cycles < 15 µm (with packaging) - From 20 mm² to large area (shadow mask) - Down to 100 x 100 µm (photolithography) IC (Si), polymer, ceramic, PCB Solid state not flammable no leakage 19

20 15 µm Evolution of CEA Microbatteries prototypes First Integration of Microbatteries on IC Microbatteries on 6 wafers Microbatteries in 8x8 BGA package 2009 Microbatteries on 8 wafers 2010 First Microbatteries Production line 2011 Microbatteries on 8 wafers 5x5 LGA package From 2 cm² to 25 mm² microbatteries (4 wafer, Thick encapsulation) Microbatteries en cours de test x 100 µm Microbatteries array for high voltage 2002 Microbatteries on flexible substrate Microbatteries SR compatible First Prototype (4 wafer, Thick encapsulation) First microbatteries with thin film encapsulation (4 wafer) 20

21 Conclusions Microbattery Technology Available with different packaging solutions Solder Reflow compatibility for some of them Industrialization on the road Microsensors powering Hybrid system with energy harvesters Depending on applications 21