Review—In Situ Polymerization for Integration and Interfacial Protection Towards Solid State Lithium Batteries

Abstract

Lithium ion batteries using liquid electrolytes often face challenges of safety issues. Polymer electrolytes can effectively solve this problem. Traditional preparation of polymer electrolytes is solution-casting method, which is complicated in practical application. Simultaneously, this ex-situ polymer electrolytes prepared by conventional method exhibits poor interfacial contact with electrodes. Fortunately, the emerging in-situ polymerization of solid state polymer electrolytes simplifies the preparation and forms an integrated interface for better interfacial compatibility in solid state lithium batteries. It is certain that solid state lithium batteries via in-situ polymerization exhibit various functionality: (1) forming integrated interface to enhance interfacial compatibility; (2) inhibiting the dissolution of transition metal ions; (3) suppressing the growth of lithium dendrites; (4) Improving the cycle performance of silicon anodes; (5) inhibiting the shuttling effect of polysulfides; (6) promoting battery performance of post-lithium batteries. Therefore, the review mainly considers and discuss the up-to-date research progress and insights on scientific issues underpinning solid state lithium batteries via in-situ polymerization strategy. Moreover, the challenges and perspectives of developing solid state lithium batteries via in-situ polymerization are discussed as well. We believe that this review will shed light on scientific and practical issues in the development of high-performance solid state lithium batteries.

Organoboron‐Containing Polymer Electrolytes for High‐Performance Lithium Batteries

“…[50][51][52][53] Except for the inherent properties of polymer materials, the preparation methods of GPEs have significant influence on the electrochemical and safety performance of GPEs, which can be categorized into ex situ and in situ methods. [54,55] The inevitable process of ex situ methods is that the obtained dry polymer membranes are soaked in LEs to get GPEs. [56] In a representative in situ process, a stoichiometric ratio of the monomers and initiator is dissolved in a LE to form a precursor solution.…”

“…Recently, in situ cationic polymerization initiated by electrolyte salts has attracted great attention. [54,112,113,114] For instance, due to LiDFOB has one oxalate-and two fluoro-substituting groups, it undergoes certain disproportionation reactions at elevated temperatures to produce lithium tetrafluoroborate (LiBF 4 ) and lithium bis(oxalato)borate (LiBOB). The anion of LiBF 4 could be considered as F complexed by the Lewis acid BF 3 , which may combine trace water to form H + (BF 3 OH) − to initiate the cationic polymerization reaction.…”

In situ preparation of gel polymer electrolyte for lithium batteries: Progress and perspectives

“…[4][5][6][7] Idealized electrolytes should be a good lithium-ion conductor with high chemical stability and do not cause other parasitic reactions on electrode surface except for the transfer of Li + . [8][9][10][11] Although the conventional organic liquid electrolytes (LEs) have high ionic conductivity, their inherent instabilities such as volatility, flammability, and other shortcomings still hinder the practical applications in Li batteries (LBs) with pure Li-metal anode. [12][13][14][15][16][17] Besides, continuous side reactions may occur between LEs and metallic Li, which would cause consumption of electrolyte and uncontrolled growth of lithium dendrites, resulting in premature battery failure and even disastrous safety problems.…”

Advancing towards a Practical Magnesium Ion Battery

“…A main issue that must be studied in depth is the chemical compatibility between the polymers and the Mg anode [ 118 ]. The preparation based on in situ polymerization could improve the interface compatibility [ 119 ]. Another shortcoming is the flammability of some organic compounds used as plasticizers in the polymer gel electrolytes.…”