Posting of Circular and Notice of General Meeting.

11 September 2025

Invinity Energy Systems plc

("Invinity" or the "Company")

Posting of Circular and Notice of General Meeting

Further to the announcement on 9 September 2025 regarding a £25m Investment and New Strategic Partner, Invinity Energy Systems plc (AIM: IES) (OTCQX: IESVF) confirms that the shareholder Circular, providing further details of the Subscription and seeking shareholder approval for the Subscription, will be posted to shareholders today. The Circular contains a Notice of General Meeting to be held at 11.00 a.m. (UK time) on 29 September 2025.

A copy of the Circular, Notice of Meeting and Form of Proxy are available from the Shareholder Documents section of the Company's investor portal https://invinity.com/investors/shareholder-documents/. Other than where defined, capitalised terms used in this announcement have the meanings given to them in the announcement released by the Company at 8.06 a.m. (UK time) on 9 September 2025.

Please note that only formal business will be conducted during the General Meeting and there will be no presentations given by management. Due to capacity constraints, shareholders wishing to attend the General Meeting are requested to RSVP via ir@invinity.com no later than 5.00 p.m. on Friday 26 September 2025, being the last working day prior to the meeting. The Company also intends to upload a recording of the formal business of the General Meeting to its website.

Voting

Shareholders are strongly encouraged to appoint the Chair of the General Meeting as their proxy so that their vote will be counted if they (or any other proxy they might otherwise appoint) are not able to attend. Note that submitting a proxy will not preclude shareholders from attending and voting at the General Meeting in person if they wish to do so.

Completed forms of proxy must be scanned and emailed to #UKCSBRS.ExternalProxyQueries@computershare.co.uk or submitted via post. Completed proxies must be received by the registrar no later than 11.00 a.m. on Thursday 25 September 2025, being two working days prior to the meeting, in order to be valid.

For assistance in submitting forms of proxy please email ir@invinity.com.

Timetable of Principal Events

Notes to timetable:

1.     Each of the times and dates above is subject to change. Any such change will be notified by an announcement on a Regulatory Information Service.

2.     All of the above times refer to London time.

3.     All events listed in the above timetable following the General Meeting are conditional upon the passing of the Resolutions at the General Meeting.

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Enquiries:

Notes to Editors

Invinity Energy Systems plc (AIM: IES) (OTCQX: IESVF) manufactures vanadium flow batteries for large-scale, high-throughput energy storage requirements of business, industry and electrical networks.

Invinity's factory-built flow batteries run continually with no degradation for over 30 years, making them suitable for the most demanding applications in renewable energy production. Energy storage systems based on Invinity's batteries are safe, reliable, and economical, and range in size from less than 250 kilowatt-hours to tens of megawatt-hours.

Invinity was created in April 2020 through the merger of two flow battery industry leaders: redT energy plc and Avalon Battery Corporation. With more than 190 MWh of systems deployed, contracted for delivery or awarded for projects across more than 90 sites in 17 countries, Invinity is active in all major global energy storage markets and has operations in the UK, Canada, USA and China. Invinity Energy Systems plc is quoted in the UK on AIM and trades in the USA on OTCQX.

To find out more, visit invinity.com, sign up to our monthly Investor Newsletter here or contact Investor Relations on via +44 (0)20 4551 0361 or ir@invinity.com.