摘要
新型高比能氟化碳(CF_(x))材料不断涌现,使Li/CF_(x)原电池的比能量/比功率特性持续提升,特别是功率型Li/CF_(x)电池已开始用于小型商业化动力系统中,可能成为比能量最高的动力型锂原电池。但不同类型CF_(x)材料制备的Li/CF_(x)锂原电池的自放电情况尚缺乏比较研究。本文选择4种典型的新型CF_(x)材料,根据其应用目标分为能量型和功率型材料,其中2种能量型CFx的F/C比接近1,具有更稳定而饱和的C—F化学键,而2种功率型CF_(x)材料F/C比略低,离子型C—F键更多,具有更好的导电性和更好的倍率性能。通过工业化设备工艺制备成的BR18650型Li/CF_(x)原电池经55℃高温储存后,无论是否放电过,能量型电池的自放电率几乎为0,具有长寿命货架储存特性;而功率型电池55℃储存后,放电深度(DOD)越高的电池的内阻越大、自放电率也越大,锂原电池常用的预放电处理工艺会导致功率型电池的自放电率上升,意味着功率型电池一旦预放电激活后就应立即投入使用。功率型电池间歇式使用会导致其自放电率增大和内阻增加,原因可能是松散LiF保护膜的破坏造成新鲜CF_(x)界面暴露于电解液中继续反应,但能量型CF_(x)材料因其具有更多稳定的饱和C—F共价键而影响较小。
The emergence of new high specific energy fluorinated carbon(CF_(x))materials has continuously improved the specific energy/specific power characteristics of Li/CF_(x) primary batteries,especially the power type Li/CF_(x) batteries have begun to be used in small commercial power systems and may become the power type lithium primary batteries with the highest specific energy.However,there is a lack of comparative study on the self-discharge of Li/CF_(x) lithium primary batteries prepared from different types of CF_(x) materials.This article selects four typical novel CF_(x) materials that are divided into energy type and power type materials according to their applications,among which two energy type CF_(x) materials have F/C ratios close to 1 and more stable and saturated C-F chemical bonds,while two power type CF_(x) materials have lower F/C ratios and more ionic C-F bonds,resulting in better conductivity and rate performance.After being stored at a high temperature of 55℃,the self-discharge rate of the industrially prepared BR18650 Li/CF_(x) battery,regardless of whether it has been discharged or not,is almost zero,making it suitable for long-life shelf storage.However,for power batteries stored at 55℃,the higher the depth of discharge(DOD),the greater the internal resistance and self-discharge rate of the battery.The pre-discharge treatment that is commonly used in lithium primary battery industry can lead to an increase in the self-discharge rate of power type batteries,which means that power type batteries should be put into use immediately after pre-discharge activation.Intermittent use of power type batteries can lead to an increase in their self-discharge rate and internal resistance,which may be due to the damage of the loose LiF protective film causing the fresh CF_(x) interface to be exposed to the electrolyte and continuous reaction,but the energy type CF_(x) material has less impact due to its more stable saturated C-F covalent bonds.
作者
杨微
李治国
赖彩婷
赵瑞瑞
李瑀
周盈科
黄依玲
朱立才
封伟
王文龙
袁中直
YANG Wei;LI Zhiguo;LAI Caiting;ZHAO Ruirui;LI Yu;ZHOU Yingke;HUANG Yiling;ZHU Licai;FENG Wei;WANG Wenlong;YUAN Zhongzhi(EVE Energy Co.Ltd,Huizhou 516006,Guangdong,China;School of Materials Science and Engineering,Tianjin University,Tianjin 300072,China;The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China;School of Chemistry,South China Normal University,Guangzhou 510006,Guangdong,China;Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China)
出处
《储能科学与技术》
CAS
CSCD
北大核心
2024年第11期3742-3753,共12页
Energy Storage Science and Technology
关键词
锂/氟化碳电池
原电池
自放电率
lithium/carbon fluoride battery
primary battery
self-discharge rate
作者简介
第一作者:杨微(1995-),女,硕士,研究方向为锂原电池研发,E-mail:085265@evebattery.com;通信作者:赖彩婷,硕士,研究方向为锂电池,E-mail:caitinglai1991@163.com;李瑀,教授,研究方向为氟化物在储能器件中的应用,E-mail:2022500016@buct.edu.cn;袁中直,教授,研究方向为电化学及电化学储能材料与器件,E-mail:yuanzz@scnu.edu.cn。
