Thermoelectric power generation by n-p junction type cell module

Transcription

1 Improvement of Thermoelectric Energy Conversion by Hyper-structural Control 10-2 n-bi 2 Te 3 NaCo 2 O 4 -poly Atomic-nano scale control electrical conductivity phonon scattering Nano-micron scale control grain boundary grain alignment Figure-of-merit, Z/K N-FeSi Al-doped ZnO Sr-Ca 2 Co 2 O 5 -poly ZT=1 n-sige SrPbO 3 -SiC Li doped NiO Figure of merit: Z = σ α2 κ Temperature / K σ:electrical conductivity α:seebeck cofficient κ:thermal conductivity

2 Thermoelectric power generation by n-p junction type cell module Thermoelectric heater module Thermoelectric ceramic module cooling stage

3 An example of Highly Interactive Materials --- denox without external energy supplying --- Heat source De-NOx Electrochemical Cell Thermoelectric modulel Demonstration of the concept of an interactive material working as a device for NOx decomposition without any external energy or fuel by using the converted energy from exhaust gas heat to supply the electrical current to the electrochemical cell.

4 Summary of electrochemical reactors for NOx /PM decomposition 1.For the first time an Electrochemical cells with multi layers electro-catalytic electrode for high selectivity of NOx decomposition and with a low value of cell operating current and power was designed. 2. Nano-structure control of electro-catalytic electrode was effective to dramatic improvement of de-nox property of the cell. NOx-PM simultaneous purifying was realized by using oxygen radical reaction. 3. An interactive ceramic reactor consisted of de-nox cell with thermo-electric module revealed 20%NOx decomposition without external power supply.

5 Nanostructured electrochemical reactors for micro SOFCs Application of Advanced Ceramic Reactor high efficiency on energy conversion and selective reaction Ceramic reactor Nanotechnology Fuel Cells Cube Cell module APU for Vehicles Environment Purifying NO x N 2 +O 2 C H 4 C O +H 2 2e O 2- Chemical Syntheses H 2 Station O 2 +N 2 N 2

6 R&D Target Electrical Efficiency (%) Power output vs Electrical Efficiency Micro SOFC PEFC PAFC SOFC Gas Engine SOFC+GT MCFC Lean-burn GE, Atkinson cycle GE Gas Turbine ,000 Power Output (kw)

7 APU applications for automobile Near Future Applications Developers SOFC-APU Webasto Heavy Duty Truck (Diesel ICE 3 6 kw) Delphi Gen1 204kg, 155L Future Refrigerator Van (10-20 kw) Passenger Car (Alternative Generator 3-10kW) Key feature ; Compactness and Cost Delphi Gen3 3.6kW, 70kg, 63L Startup 75min Technical Hurdle ; Rapid Startup Target (goal) Volume 5L Startup 5-15min

8 Micro Tubular SOFC in the World US: Advanced Package for Military Applications Primary Idea of Micro tubular SOFC ; Kendall / Sammes (UK) Adaptive Materials (US) EU: Original Idea Adelan (UK) P=75W, 250W Startup10-15min, LPG Fuel, T=700C Mesoscopic Devices (US) TOTO (Japan) AIST (Japan) ALPPS(Austria) ND50H; V=7L, W=5kg, Startup 15min NanoDynamics (US) JAPAN: Advanced Core Modules

9 Research objective of the Advanced Ceramic Reactor Weak points of conventional SOFC 1)Startup-stop issue 2)High temperature operation (durability) 3)Cost reduction Solutions 1)Rapid startup and stop Small size unit cells 2)Reduced temperature operations from >800C to C 3)Innovative low cost Improve power density per unit volume Concept of Ceramic reactor 1) sub-millimeter tube unit cells (0.5W/cm or under) Porous Cathode For rapid startup, Enhance electrode areas 2) Parallel integrated cell (pile of unit cells, 2kW/L) 3) Advanced ceramic processing and materials (nano - micro structure control) Accumulation of high performance tubular SOFCs

10 Development of Advanced Ceramic Reactor Air(O 2 ) Fuel(H 2 etc.) Porous cathode (LSCF) CGO/ScSZ Electrolyte 1cm Micro Tubular Cells Dense Electrolyte Anode (Ni-CGO) 20 Micro tube Cube matrix Porous Cathode seal Anode current collectorctor Porous Anode Cells integrate d Cube Cube power density (kw / L) 円小型今回の 筒チューブターゲット 形 Tubular SOFC Small Tube Cell Micro Tube Ceramic Reactor (Our Target) Cell diameter (mm) Air seal Interface construction Fuel Ceramic Reactor Module

11 Scheme of the research project 1. Development of highly active materials at low temperature operation 2. Development of the three dimensional fabricating process of reactors The Advanced Ceramic Reactor Project (NEDO)July 2005 March 2010 Total budget; 2.1 Billion Yen 3. Evaluation of prototype module and application of advanced ceramic reactors Mie University, Hosokawa Powder Technology Research Institute, Kyocera Corporation AIST, FCRA, Connecticut University, Toho Gas,CRIEPI, Denso Corporation Natl.Inst.Advanced Industrial Science and Technl.(AIST), Fine Ceramics Research Association (FCRA:NGK,NGKNTK), Nagoya University, Japan Fine Ceramics Center, Toho Gas Co., Ltd., Central Research Institute of Electric Power Industry(CRIEPI) Core research site for the development of fabricating technology

12 Selected Results 1. Development of highly active materials at low temperature operation Hosokawa Powder Technology Research Institute >Ni-SDC cermet anode fabricated from NiO-SDC composite powder Schema of the material development for electrodes and electrolytes Nanoparticle synthesis nano meter - micron meter scale Composite Hybridization composite Hyper-structural and compositional control of electrodes and interfaces network and distribution of pores and matrix hybrid control of shape, size distribution and composition fine dispersion

13 Ni-GDC NNi- Nī- GDC cermet cermet anode anode fabricated from from NiO-GDC O - GDC composite powder Morphology of cermet anode Ni-GDC/GDC/LSCF anode supported cell φ80mm Ni 1um Ce LSCF cathode GDC electrolyte 1um 1um Ni-GDC anode 10μm Ni-SDC anode supported cell with thin SDC electrolyte achieved high electrical performance at lower operation temperature ( 650ºC). C ellv oltage (V ) N i-g D C /G D C /LSC F の発電性能 測定 測定 測定 0.0 PD C urrent density (A/cm 2) pow er density (W /cm 2)

14 Selected Results AIST 2. Development of the three dimensional fabricating process of reactors Fabrication of micro-tubular GDC cell and cell characterization Cell Preparation mmφ NiO-GDC anode tube Dip-coating of electrolyte 1.6mm diameter Micro SOFC 0.8mm diameter Electrolyte Co-fired at 1450 C for 6h Cathode Anode tube Dip-coating of cathode Sintered at 1000 C for 1 h. 0.8mm diameter anode tube NiO-GDC/GDC(20µm)/LSCF-GDC Power density, W/cm 2 Current density, A/cm 2 The micro SOFC fabricated as a tubular structure of 1 cm in length and mm in diameter and revealed power densities of 1 W/cm2 at 570 C, was obtained ---This value is on the world s highest level in SOFCs with ceria based electrolytes ---

15 Cell stack module fabrication AIST/FCRA(NGKNTK) 1cm Developing Micro tubular IT- SOFC < 2.0mmΦ Improvement of fabrication technology for the stacked Modules(Cube) Air fuel Integration technology of compact power modules

16 Successful Development of a Small, High-Performance Micro Fuel Cell Bundle - Realizes more than two watts of output power in a unit size of a sugar cube (one cubic centimeter) below 600 (2W/cm ) Voltage 電圧,V (V) Power (W) 電力, W 電流,A Current (A) Successful development of a small high power solid oxide fuel cell (SOFC) cubic bundle integrated very fine ceramic tubes in a volume of a sugar cube. The SOFC bundle generates the world s highest output power density (two watts per cubic centimeter) at an operating temperature of below 600 C, previously considered not possible for SOFCs that are normally operated at high temperatures.

17 Fabrication of Micro honeycomb SOFC 16 16cells/cm 2 0.7mm 0.7mm LSM honeycomb GDC NiO/GDC NiO/GDC GDC LSM 100μm 10μm

18 Voltage (V) Volumetric power density (W/cm 3 ) Temp ( C) V oltage (V) start N2 in 5min H2 in OCV Temp Time (sec) 1 0 OCV (V) Voltage (V) C cyclic testing (over 100 times) Current density (A/cm 2 ) Anode アノード側 side 導電部材 (SUS) connector m A /cm 2 100m A /cm 2 H 2 off air in 0.6 N 2 in H 2 in 0.4 LSM /ScSZ N 2 in /N io -G D C 0.2 Redox 700 C Tim e (sec) stacking 接続例 カソード側 Cathode side 2 1 Honeycomb stack Honeycomb 600 C Current density (A/cm 2 ) ハニカムスタック評価結果例 0

19 Inter connector materials JFCC Flexible sealing sheet (insulating) sheet Porous electrodes Conductive sheet Current-path design 3 種類のシール材を用いた導電パスの構築 インターフェース材料 Interface materials Electrolyte 固体電解質 Cube キューブ Anode 燃料極 Cathode 空気極 e - O 2- 導電パス構築 Current path チューブ e - e - Tube Ag-Si-Ge alloy e - O 2- e - e - Conductive 導電シート材 sheet Insulating 絶縁シート材 sheet 導電 Conductive/ / 絶縁シート材 Insulating sheet

20 Selected Results 3. Evaluation of prototype module and application of advanced ceramic reactors 30 mm 30 mm 50 mm Prototype type bundle Fuel Model Size(with manifold) : 30 x 30 x 110 mm Size(electrode) : 30 x 30 x 30 mm Tubes : 36 Ni-GDC tubes current collector : Alloy plate + Ag mesh Air Fig. Photograph of the prototype bundle composed of 36 Ni-GDC single cells. E / V W I / A The performances of prototype o C. Fuel : H ml/min, N ml/min Power / W

21 Application of advanced ceramic reactors Analysis and evaluation of materials, cells, stacks and prototype modules to demonstrate utilities of the reactors by TOHO gas Domestic stationary power sources System concept Demonstration of prototype module as APU unit for Automobile by DENSO Test module Fuel Tank Engine Alternator Battery Ceramic Reactor kw System Package Alternator Micro SOFC module >rapid start-up/shut-down, fuel High performance compact APU

22 Portable power sources (clean & quiet) Mock-up model (200W class)

23 Summary of Micro SOFC development >Advanced ceramic reactor project aims to develop - materials for electrolytes and electrodes of electrochemical reactors that can be used at lower operation temperature and - a manufacturing process technology for integrating and arranging structure of the materials in the micro level >Goals are to develop a prototype micro-sofc module that generates more than 2kW/L of power density at 650 C or lower, with a rapid startupshutdown performance for application to APU and cogeneration power unit and others. >Micro tubular SOFCs with mm diameter have been successfully fabricated. Advanced ceramic processing method developed in this project enabled to realize that the single tubular SOFC with ceria based electrolyte showed cell performance of over 1W/cm 2 at 570 C. *over 3W/cm C by a sugar cube like cell-stack **Honeycomb SOFC (over 250 cells/cm 3 ) and successful stacking process >The new micro tubular SOFCs will be applied to build a compact power device with robustness by working in an accumulated cube-type stack. >>> test module / prototype - by