Form DEFA14A - Additional definitive proxy soliciting materials and Rule 14(a)(12) material

UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549FORM 8-KCURRENT REPORTPURSUANT TO SECTION 13 OR 15(d)OF THE SECURITIES EXCHANGE ACT OF 1934Date of Report (Date of earliest event reported):October 9, 2024ARCADIUM LITHIUM PLC(Exact name of registrant as specified in itscharter) Bailiwick of Jersey 001-38694 98-1737136 (State or other jurisdiction of incorporation or organization) (Commission File Number) (I.R.S. Employer Identification No.) 1818 Market Street, Suite 2550 Philadelphia, PA United States 19103 Suite 12, Gateway Hub Shannon Airport House Shannon, Co. Clare Ireland V14 E370 (Address of principal executive offices, includingzip code) 215-299-5900 353-1-6875238 (Registrant’s telephone number, includingarea code)N/A(Former name or former address, if changed sincelast report) Check the appropriate box below if the Form 8-K filing is intendedto simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐ Written commu...