锂电后起之秀–钛酸锂 LTO – The new kid on the Li-ion battery block 薛嘉渔 首席科学家 山东玉皇新能源科技有限公司 December. 2017

目录 1 2 3 CONTENTS 钛酸锂电池是一个优秀的电化学体系 钛酸锂电池的应用市场在哪里？ 动力电池类型 Types of power Li-ion batteries 2 钛酸锂电池是一个优秀的电化学体系 LTO battery is an excellent EC system 3 钛酸锂电池的应用市场在哪里？ Where’s the applications for LTO battery?

1 动力电池类型 Types of power Li-ion batteries

Requirement of Li-ion cells for xEV Safety Consistency (or Reliability) Long cycle life (10-15 yrs?) High power density (HEV) High energy density (BEV) Low cost (5-10% lower/year?) High & low temperature performance (-40 to 65oC )

Aluminum cased prismatic cells for xEV

Aluminum cased Li-ion cell for xEV

Pouch prismatic cells for xEV

Pouch prismatic cells for xEV

How the cell fails (the nightmare for LIB engineers)? Abnormal amount of heat generated internally in the cell mostly from graphite anode could lead to fire or explosion!

The expansion/contraction of the LIB 起始状态 Initial state 经长期循环 After extensive cycling The internal mechanical stress of electrodes caused by charging/discharging graphite leads to electrode disconnection in the cell!

2 钛酸锂电池是一个优秀的电化学体系 LTO battery is an excellent EC system

Brief history of LTO In 1971, spinel type Li4Ti5O12 or LTO was first reported by Deschanvres et al. Deschanvres A, Raveau B, Sekkal Z. Mise en evidence cristallographique d'une nouvelle solution solide de type spinelle Li1 Ti2,O4(0≤x≤0.33) [J]. Mat. Res. Bull., 1971, 6(8) : 699-704. In 1989, Colbow et al. had studied more than its structural properties but also the possibility of using LTO as an electrochemical material. Colbow K M, Dahn J R, Haering R R. Structure and Electrochemistry of the Spinel Oxides LiTi2O4 and Li4/3Ti5/3O4 [J]. J. Power Sources,1989, 26(3-4):397-402. In 1995, Ohzuku et al. referred the LTO as a “zero strained material”. Ozuku T, Ueda A, Yamamoto N. Zero-Strain Insertion Material of Li[Li1/3Ti5/3]O4 for Rechargeable Lithium Cells[J]. J. Electrochem. Soc., 1995, 142(5):1431-1435. ……..

How the LTO chemistry works? Li4Ti5O12 Spinel = AM2O4 or (AM2O4)x3 = A3M6O12 6Li+ move from 8a to 16c Space group: Fd3m a = 0.836nm 5Ti4+/1Li+ in 16d site or Oh Li+ in 8a site or Td (Disch) Li+ in 16c site or Oh (Ch) Chemical formula: Li3(Li1Ti5)O12 Discharge state: [Li+3]8a[Li+Ti4+5]16d[O2-12 ]32e Charge balanced: Li+3(Li+1Ti4+5)O2-12 Charge state: [Li+6]16c[Li+Ti3+3Ti4+2]16d[O2-12 ]32e adisch=0.836nm; aCh=0.837nm “Zero strained” crystal lattice Theoretical capacity: 175mAh/g

Is graphite the angel / devil in the Li-ion cells? Graphite is the angel! 1. OK low T performance 2. OK cycle life 3. OK charge/discharge rate 4. Cell expansion 5. High energy density (E.D.) Graphite is the devil ! Due to SEI (1-3) Intrinsic layer expansion (4) Intrinsic E.P. ≈ Li0 (5) LTO shows just the opposite of graphite : no SEI (1-3) “Zero stress” crystal lattice (4) E.P. =1.55V , safe but less E.D.!

Low/high T performance Pro’s & Con’s of LTO Safest Anode Longest cycle life Con’s of LTO Low energy density High material cost ? Cell gassing (know-how)? Market is not obvious? (educate the consumers) Targeted market & IP LTO High rate capability Cost effective Low/high T performance

Price of various anode materials

Supply/demand world of anode materials

Road to glory? How to achieve a high energy cell? A 3.5V LTO cell can be built by using 5V cathode (LiNi0.5Mn1.5O4, LCP, LCMP, … etc.) stable electrolyte systems (PC? new Li salt?) anti-oxidation separators (ceramic?) ……

Novel Anode Materials Li2TiSiO5 (LTSO) - First reported by: S. Patoux & C. Masquelier, Chem. Mater., 2002, 14,5057-68. - Y.Y. Xia et al., Energy & Environ. Sci., 2017,

Electrochemical Properties of Li2TiSiO5 Voltage range (V) Capacity (mAh/g) (1) 3.0 - 0.2 210 (2) 3.0 – 0.1 240 (3) 3.0 – 0.0 308 Li-insertion Mechanism: Conversion / Solid Solution

Full Cell Performance of LTSO / NCM The full battery delivered an average working voltage of 3.25 V and a practical specific energy of 130Wh/kg can be expected, which is larger than 75Wh/kg of commercialized LiMn2O4/Li4Ti5O12 battery.

3 钛酸锂电池的应用市场在哪里？ Where’s the applications for LTO battery?

Where’s the market for LTO batteries? 高倍率 长寿命 高低温 Where’s the market for LTO batteries? 3.1 Energy Storage（储能） 3.1.1 Renewable Energy（可再生能源） - PV（太阳能） - Wind farm（风能） 高安全 长寿命 3.1.2 Residential & Business （居民小区/商业区） - uninterrupted power supplies (UPS)（不间断电源） in banks, hospitals, database, office buildings & residential compounds（银行、医院、数据中心、办公楼、小区等） - family energy storage (FES)（家庭储能）

Where’s the market for LTO batteries? 高安全 大功率 3.1.3 Smart Grid （智能电网） - frequency regulation (FR)（调频） - peak shaving (PS)（调峰） 高安全 长寿命 长寿命 大功率 3.1.4 Remote Areas - remote areas（边远地区） - islands（孤岛运作）

Where’s the market for LTO batteries? 高寒地带 低温 长寿命 3.1.5 Cold region （寒冷地带） - Northern China, Russia, Canada, European countries…. （中国北方、俄国、加拿大、北欧 …）

Where’s the market for LTO batteries? 3.1.6 Industrial applications （工业用途） - warehouse operation, harbor machinery, folk-lift … （仓库管理、叉车、港口机械 …） 高安全 大功率 大功率 高安全 长寿命

Where’s the market for LTO batteries? 3.1.7 Military & space exploring （军事与太空探险） 高安全

Where’s the market for LTO batteries? 高安全 高倍率 3.2 Transportation（交通） 3.2.1 Fixed distance buses （固定距离公交大巴） 3.2.2 Consumer vehicles - Logistic & postal cars, （物流车，邮车） … 3.2.3 Various Passenger cars (HEV’s) （各种电动、混动乗用车） 高安全 高倍率

Where’s the market for LTO batteries? 高安全 高倍率 长寿命 China’s LTO xEV’s （我国的LTO车） 微宏动力 河北银隆 天津捷威 天康/正道 四川兴能

Where’s the market for LTO batteries? 高安全 长寿命 Toshiba’s LTO EV’s （东芝的LTO乗用车） 日本东通工推出的Style-D超小型Piana双座车 采用新日本电池的 7.2kWh NCM/LTO电池. - 5分钟充满电 - 无需BMS

Something else about the LTO tech. LTO materials & Cells Al current collector used for both anode & cathode in the LTO cells ($,wt.). PC based electrolyte provide better high/low temperature performance LTO cell is anode limited, while a graphite cell is cathode limited. As made LTO materials are hygroscopic (pH=11-12). Therefore, LTO cell manufacture is NOT a “drop in” for a conventional graphite cell manufacturing line. Environment, process and production facilities need to be modified accordingly. LTO’s 10x longer cycle life = 10x less used batteries (than graphite cells). LTO Packs No need for heater (saving on weight, space & money) No BMS is needed ($,wt.space).

Something else about the LTO tech. Applications for safe LTO technology HEV, Rail way, subway, industrial, ISS (fast charge/discharge) Auto in cold climate (low T performance) Fixed distance Bus (8 yrs service life) Family energy storage system or FESS (safety), Grid (frequency regulation) (fast discharge), ESS for wind & PV (extremely long cycle life).

Thank you for your kind attention! Further readings: 薛嘉渔等， 钛酸锂电池技术及其产业发展现状，《新材料产业,》9(2015)12-17. 薛嘉渔，中国锂电产业能否走向长治久安之路？ http://www.ciaps.org.cn/news/show-htm-itemid-14881.html Contact info: sxue2008@126.com